Synthesis of 1,3,5-trisubstituted pyrazoles

ABSTRACT

A novel process for making 1,3,5-trisubstituted pyrazoles of the type shown below from appropriate phenyl hydrazines is described.                    
     These compounds are useful as factor Xa inhibitors.

This application claims benefit of Provisional No. 60/161,666 filed Oct.21, 1999.

FIELD OF THE INVENTION

The present invention relates generally to processes for the preparationof 1,3,5-trisubstituted pyrazoles and intermediates for the synthesis ofthe same, such pyrazoles being useful as factor Xa inhibitors.

BACKGROUND OF THE INVENTION

1,3,5-Trisubstituted-pyrazole compounds of the type shown below arecurrently being studied as factor Xa inhibitors in clinical settings. Asone of ordinary skill in the art understands, clinical trials and NDAsubmissions require practical, large-scale synthesis of the active drug.

Consequently, it is desirable to find new synthetic procedures formaking 1,3,5-trisubstituted pyrazoles.

SUMMARY OF THE INVENTION

Accordingly, one object of the present invention is to provide a novelprocess for making 1,3,5-trisubstituted pyrazoles.

It is another object of the present invention to provide novelintermediates for the syntheses of the same 1,3,5-trisubstitutedpyrazoles.

These and other objects, which will become apparent during the followingdetailed description, have been achieved by the inventors' discoverythat compounds of formula I can be formed from aryl hydrazines.

DETAILED DESCRIPTION OF THE INVENTION

Thus, in a first embodiment, the present invention provides a novelprocess for preparing a compound of formula I:

wherein ring D is selected from 2-(aminomethyl)phenyl,3-(aminomethyl)phenyl, and (3-amino)benz[d]isoxazol-6-yl; and

B is 2-MeSO₂-phenyl or 2-NH₂SO₂-phenyl, the process comprising:

(a) acylating a hydrazine of formula II to form a found of formula III:

wherein ring D is selected from 2-cyanophenyl, 3-cyanophenyl,3-cyano-4-fluorophenyl, 2-(PgNHCH₂)phenyl, and 3-(PgNHCH₂)phenyl, and Pgis an amine protecting group;

(b) converting a compound of formula III to a compound of formula IV,wherein X is selected from Cl, OMs, Br, OSO₂Ph, and OTs;

(c) contacting a compound of formula IV with a base to form a dipolarcompound of formula V:

(d) contacting a compound of formula V in situ with a dipolarophile offormula VI to form a compound of formula VII, wherein Y is selected fromBr, 2-MeSO₂-phenyl, 2-MeS-phenyl, 2-NH₂SO₂-phenyl, and 2-PgNHSO₂-phenyl;

(e) converting a compound of formula VII to a compound of formula I bysubjecting it to the following reactions, which may be performed, whenapplicable, in any order:

(e1) oxidizing the pyrazoline to a pyrazole;

(e2a) when Y=Br, converting the Br group to 2-MeS-phenyl,2-SO₂Me-phenyl, or 2-SO₂NH₂-phenyl;

(e2b) when Y=2-MeS-phenyl, converting the MeS-group to MeSO₂—;

(e3a) when ring D is cyanophenyl, converting this group toaminomethylphenyl or (PgNHCH₂)phenyl;

(e3b) when ring D is 3-cyano-4-fluorophenyl, converting this ring to(3-amino)benz[d]isoxazol-6-yl; and,

(e4) when Pg is present, removing the protecting group.

In another embodiment, step (b) is performed by contacting a compound offormula III with a sulfonyl chloride in the presence of an amine base,wherein the amine base is capable of forming a tertiary amine hydrogenchloride in situ and delivering a chloride in situ to form a compound offormula IV wherein X is Cl;

wherein the sulfonyl chloride is selected from methylsulfonyl chloride,phenylsulfonyl chloride and toluenesulfonyl chloride, the amine base isselected from triethylamine, diisopropylethylamine, andN-methylmorpholine.

In another embodiment, the sulfonyl chloride is phenylsulfonyl chlorideand the amine base is diisopropylethylamine.

In another embodiment, step (b) is performed by contacting a compound offormula III with a sulfonyl chloride in the presence of an amine base,followed by contacting the resultant sulfonyl compound with a tertiaryamine hydrogen chloride to form a compound of formula IV wherein X isCl;

wherein the sulfonyl chloride is selected from methylsulfonyl chloride,phenylsulfonyl chloride and toluenesulfonyl chloride, the amine base isselected from triethylamine, diisopropylethylamine, andN-methylmorpholine.

In another embodiment, in (e) the compound of formula VII is convertedto a compound of formula I by subjecting compound VII to the followingreactions, that are performed, when applicable, in the order shown:

(e1) oxidizing the pyrazoline to a pyrazole;

(e2a) when Y=Br, converting the Br group to 2-MeS-phenyl,2-SO₂Me-phenyl, or 2-SO₂NH₂-phenyl;

(e2b) when Y=2-MeS-phenyl, converting the MeS-group to MeSO₂—;

(e3a) when ring D is cyanophenyl, converting this group toaminomethylphenyl or (PgNHCH₂)phenyl;

(e3b) when ring D is 3-cyano-4-fluorophenyl, converting this ring to(3-amino)benz[d]isoxazol-6-yl; and,

(e4) when Pg is present, removing the protecting group.

In another embodiment, in (e) the compound of formula VII is convertedto a compound of formula I by subjecting compound VII to the followingreactions, that are performed, when applicable, in the order shown:

(e1) oxidizing the pyrazoline to a pyrazole;

(e3a) when ring D is cyanophenyl, converting this group toaminomethylphenyl or (PgNHCH₂)phenyl;

(e3b) when ring D is 3-cyano-4-fluorophenyl, converting this ring to(3-amino)benz[d]isoxazol-6-yl;

(e2a) when Y=Br, converting the Br group to 2-MeS-phenyl,2-SO₂Me-phenyl, or 2-SO₂NH₂-phenyl;

(e2b) when Y=2-MeS-phenyl, converting the MeS-group to MeSO₂—; and,

(e4) when Pg is present, removing the protecting group.

In another embodiment, in (e) the compound of formula VII is convertedto a compound of formula I by subjecting compound VII to the followingreactions, that are performed, when applicable, in the order shown:

(e2a) when Y=Br, converting the Br group to 2-MeS-phenyl,2-SO₂Me-phenyl, or 2-SO₂NH₂-phenyl;

(e2b) when Y=2-MeS-phenyl, converting the MeS-group to MeSO₂—;

(e1) oxidizing the pyrazoline to a pyrazole;

(e3a) when ring D is cyanophenyl, converting this group toaminomethylphenyl or (PgNHCH₂)phenyl;

(e3b) when ring D is 3-cyano-4-fluorophenyl, converting this ring to(3-amino)benz[d]isoxazol-6-yl; and,

(e4) when Pg is present, removing the protecting group.

In another embodiment, in (e) the compound of formula VII is convertedto a compound of formula I by subjecting compound VII to the followingreactions, that are performed, when applicable, in the order shown:

(e2a) when Y=Br, converting the Br group to 2-SO₂Me-phenyl or2-SO₂NH₂-phenyl;

(e2b) when Y=2-MeS-phenyl, converting the MeS-group to MeSO₂—;

(e3a) when ring D is cyanophenyl, converting this group toaminomethylphenyl or (PgNHCH₂)phenyl;

(e3b) when ring D is 3-cyano-4-fluorophenyl, converting this ring to(3-amino)benz[d]isoxazol-6-yl;

(e1) oxidizing the pyrazoline to a pyrazole; and,

(e4) when Pg is present, removing the protecting group.

In another embodiment, in (e) the compound of formula VII is convertedto a compound of formula I by subjecting compound VII to the followingreactions, that are performed, when applicable, in the order shown:

(e3a) when ring D is cyanophenyl, converting this group toaminomethylphenyl or (PgNHCH₂)phenyl;

(e3b) when ring D is 3-cyano-4-fluorophenyl, converting this ring to(3-amino)benz[d]isoxazol-6-yl;

(e1) oxidizing the pyrazoline to a pyrazole;

(e2a) when Y=Br, converting the Br group to 2-MeS-phenyl,2-SO₂Me-phenyl, or 2-SO₂NH₂-phenyl;

(e2b) when Y=2-MeS-phenyl, converting the MeS-group to MeSO₂—; and,

(e4) when Pg is present, removing the protecting group.

In another embodiment, in (e) the compound of formula VII is convertedto a compound of formula I by subjecting compound VII to the followingreactions, that are performed, when applicable, in the order shown:

(e3a) when ring D is cyanophenyl, converting this group toaminomethylphenyl or (PgNHCH₂)phenyl;

(e3b) when ring D is 3-cyano-4-fluorophenyl, converting this ring to(3-amino)benz[d]isoxazol-6-yl;

(e2a) when Y=Br, converting the Br group to 2-MeS-phenyl,2-SO₂Me-phenyl, or 2-SO₂NH₂-phenyl;

(e2b) when Y=2-MeS-phenyl, converting the MeS-group to MeSO₂—;

(e1) oxidizing the pyrazoline to a pyrazole; and,

(e4) when Pg is present, removing the protecting group.

In a second embodiment, the present invention provides a novel processfor preparing a compound of formula I:

wherein ring D is 2-(aminomethyl)phenyl, 3-(aminomethyl)phenyl, or(3-amino)benz[d]isoxazol-6-yl and B is 2-MeSO₂-phenyl or2-NH₂SO₂-phenyl, the process comprising:

(f) acylating a hydrazine of formula II to form a compound of formulaIII:

wherein ring D is selected from 2-cyanophenyl, 3-cyanophenyl,3-cyano-4-fluorophenyl, 2-(PgNHCH₂)phenyl, and 3-(PgNHCH₂)phenyl, and Pgis an amine protecting group;

(g) converting a compound of formula III to a compound of formula IV,wherein X is selected from Cl, OMs, Br, OSO₂Ph, and OTs;

(h) contacting a compound of formula IV with a base to form a dipolarcompound of formula V:

(i) contacting a compound of formula V in situ with a dipolarophile offormula VIa to form a compound of formula VIIa, wherein R is selectedfrom H, Me, Et, and n-Pr;

(j) converting a compound of formula VIIa to a compound of formula I bysubjecting it to the following reactions, which may be performed, whenapplicable, in any order:

(e1) oxidizing the pyrazoline to a pyrazole;

(j1) when R is other than H, hydrolyzing the compound of formula VIIa toits corresponding acid;

(j2) when R is H, contacting the acid formula VIIa with an aniline offormula Vib to form an amide;

wherein Y is selected from Br, 2-MeSO₂-phenyl, 2-MeS-phenyl,2-NH₂SO₂-phenyl, and 2-PgNHSO₂-phenyl;

(e2a′) when Y=Br, converting the Br group to 2-MeS-phenyl,2-SO₂Me-phenyl, or 2-SO₂NH₂-phenyl;

(e2b′) when Y=2-MeS-phenyl, converting the MeS-group to MeSO₂—;

(e3a) when ring D is cyanophenyl, converting this group toaminomethylphenyl or (PgNHCH₂)phenyl;

(e3b) when ring D is 3-cyano-4-fluorophenyl, converting this ring to(3-amino)benz[d]isoxazol-6-yl; and,

(e4) when Pg is present, removing the protecting group.

In another embodiment, the present invention provides novel compounds offormula IX:

wherein ring D is 2-cyanophenyl, 2-(PgNHCH₂)phenyl,2-(aminomethyl)phenyl, 3-cyanophenyl, 3-(PgNHCH₂)phenyl,3-(aminomethyl)phenyl, 3-cyano-4-fluorophenyl, and(3-amino)benz[d]isoxazol-6-yl;

Y′ is selected from Br, H, PgHNSO₂Ph, H₂NSO₂Ph, 2-MeSPh, and 2-MeSO₂Ph;bond a is absent or is a single bond; and,

Pg is an amine protecting group selected from Boc and TFA.

In another embodiment, the present invention provides novel compounds offormula X:

wherein R is selected from H, Me, Et, and n-Pr;

ring D is 2-cyanophenyl, 2-(PgNHCH₂)phenyl, 2-(aminomethyl)phenyl,3-cyanophenyl, 3-(PgNHCH₂)phenyl, 3-(aminomethyl)phenyl,3-cyano-4-fluorophenyl, and (3-amino)benz[d]isoxazol-6-yl;

bond a is absent or is a single bond; and,

Pg is an amine protecting group selected from Boc and TFA.

Definitions

The present invention can be practiced on multigram scale, kilogramscale, multikilogram scale, or industrial scale. Multigram scale, asused herein, is preferable in the sale wherein at least one startingmaterial is present in 10 grams or more, more preferable at least 05grams or more, even more preferably at least 100 grams or more.Multikilogram scale, as used herein, is intended to mean the scalewherein more than one kilo of at least one starting material is used.Industrial scale as used herein is intended to mean a scale which isother than a laboratory sale and which is sufficient to supply productsufficient for either clinical tests or distribution to consumers.

As used herein, equivalents are intended to mean molar equivalentsunless otherwise specified.

As used herein, the term “amino protecting group” (or “N-protected”)refers to any group known in the art of organic synthesis for theprotection of amine groups. As used herein, the term “amino protectinggroup reagent” refers to any reagent known in the art of organicsynthesis for the protection of amine groups that may be reacted with anamine to provide an amine protected with an amine-protecting group. Suchamine protecting groups include those listed in Greene and Wuts,“Protective Groups in Organic Synthesis” John Wiley & Sons, New York(1991) and “The Peptides: Analysis, Synthesis, Biology, Vol. 3, AcademicPress, New York, (1981), the disclosure of which is hereby incorporatedby reference. Examples of amine protecting groups include, but are notlimited to, the following: 1) acyl types such as formyl, trifluoroacetyl(TFA), phthalyl, and p-toluenesulfonyl; 2) aromatic carbamate types suchas benzyloxycarbonyl (cbz) and substituted benzyloxycarbonyls,2-(p-biphenyl)-1-methylethoxycarbonyl, and 9-fluorenylmethyloxycarbonyl(Fmoc); 3) aliphatic carbamate types such as tert-butyloxycarbonyl(Boc), ethoxycarbonyl, diisopropylmethoxycarbonyl, and allyloxycarbonyl;4) cyclic alkyl carbamate types such as cyclopentyloxycarbonyl andadamantyloxycarbonyl; 5) alkyl types such as triphenylmethyl and benzyl;6) trialkylsilane such as trimethylsilane; and 7) thiol containing typessuch as phenylthiocarbonyl and dithiasuccinoyl.

Amine protecting groups may include, but are not limited to thefollowing:2,7-di-t-butyl-[9-(10,10-dioxo-10,10,10,10-tetrahydrothio-xanthyl)]methyloxycarbonyl;2-trimethylsilylethyloxycarbonyl; 2-phenylethyloxycarbonyl;1,1-dimethyl-2,2-dibromoethyloxycarbonyl;1-methyl-1-(4-biphenylyl)ethyloxycarbonyl; benzyloxycarbonyl;p-nitrobenzyloxycarbonyl; 2-(p-toluenesulfonyl)ethyloxycarbonyl;m-chloro-p-acyloxybenzyloxycarbonyl; 5-benzyisoxazolylmethyloxycrbonyl;p-(dihydroxyboryl)benzyloxycarbonyl; m-nitrophenyloxycarbonyl;o-nitrobenzyloxycarbonyl; 3,5-dimethoxybenzyloxycrbonyl;3,4-dimethoxy-6-nitrobenzyloxycarbonyl;N′-p-toluenesulfonylaminocarbonyl; t-amyloxycarbonyl;p-decyloxybenzyloxycarbonyl; diisopropylmethyloxycarbonyl;2,2-dimethoxycarbonylvinyloxycarbonyl; di(2-pyridyl)methyloxycarbonyl;2-furanylmethyloxycarbonyl; phthalimide; dithiasuccinimide;2,5-dimethylpyrrole; benzyl; 5-dibenzylsuberyl; triphenylmethyl;benzylidene; diphenylmethylene; and, methanesulfonamide.

Synthesis

By way of example and without limitation, the present invention may befurther understood by the following schemes and descriptions.

This reaction involves the acetylating of an arylhydrazine (II) or asalt thereof (e.g., HCl) with an acetylating reagent (e.g.,trifluoroacetic anhydride (TFAA)) to produce the correspondingaceytlated arylhydrazine (III). From about 1.0-1.1 equivalents ofacetylating reagent are used, preferably about 1.0 equivalent,especially when the reaction is run on large scale. Surprisingly, nobase is necessary to run the acetylation. A base may be used, ifdesired. The preferred reaction temperature is about 0-25° C. In orderto control the internal temperature and maintain it at or below 25° C.,the acetylating reagent addition rate is adjusted accordingly. Suchtemperature control avoids formation of the bis-trifluoroacetylatedby-product. The reaction is normally complete in about 1-2 h at from0-25° C. Preferably, THF is used as solvent, though other aproticsolvents can be used. The product is isolated by stripping off most ofthe solvent (i.e., THF) in vacuo when the reaction is complete andtitrating the residue with a non-polar solvent, such as a hydrocarbon(e.g., heptanes) to precipitate the product, that is pure enough tocarry forward without further purification.

The 1,3-dipole used in the present invention is a nitrileimine (V),which is generated by treating its precursor (IV), such as hydrazonoylhalide (IVa or IVb) or a hydrazonoyl sulfate (IVc, IVd, or IVe), with abase. The in situ generated nitrileimine (V) can be directly reactedwith a dipolarophile, such as a substituted alkene, to produce thecorresponding cycloaddition product, such as a substituted pyrazoline.The procedure for preparation of the corresponding hydrazonoyl bromide(IVa) and hydrazonoyl chloride (IVb) has been previously described (seeChem. Pharm. Bull. 1988, 36(2), 800).

About 1.0-1.5 equivalents of sulfonyl chloride is used, with thepreferred molar ratio being about 1.05-1.1. Preferred sulfonyl chloridesare methyl sulfonyl chloride, phenyl sulfonyl chloride and toluenylsulfonyl chlorde, with phenyl sulfonyl chloride being most preferred. Abase is used to initiate the sulfonation reaction. The preferred base isa trialkylamine (pKa 10-11), such as triethylamine ordiisopropylethylamine (Hunig's base), or a cyclic tertiary amine (pKa7-8), such as N-methylmorpholine (NMM), with diisopropylethylamine beingmost preferred. When substrate (III) contains electron-withdrawingfunctional group(s) on its aromatic ring, a cyclic tertiary amine is thepreferred base; on the other hand, when substrate (III) containselectron-donating functional group(s) on its aromatic ring, atrialkylamine is preferred. The preferred reaction temperature is from0-25° C. The reaction time depends on the reactivity of the substrate(III) and the sulfonating agent. Normally, the sulfonation reaction iscomplete in 1-4 h at 0-25° C. The preferred solvents for thissulfonation reaction are ethyl acetate (EtOAc), toluene or methylenechloride, with EtOAc being most preferred.

The regioselectivity of the sulfonation reaction (oxygen vs nitrogen)depends mainly on the reactivity of substrate (III). SelectiveO-sulfonation can be reached (oxygen vs nitrogen>20:1) when anelectron-deficient arylhydrazine (III) (e.g., trifluoroacylatedarylhydrazine) is used. However, the regioselectivity is reduceddramatically (oxygen vs nitrogen<4:1) when an electron-enrichedtrifluoroacylated arylhydrazine (III) is employed. Therefore, thenucleophilicity and basicity of the nitrogen atom connected to thearomatic ring is greatly affected by the ring substitution pattern. Thechoice of base can also affect this selectivity.

The present invention also provides a novel and efficient preparation ofhydrazonoyl sulfonates (IVc, IVd, and IVe) as the corresponding1,3-dipole precursors in the cycloaddition reaction.

The hydrazonoyl sulfonates (IVc, IVd, or IVe) can be readily transformedin situ into the corresponding hydrazonoyl chloride (IVb) by reactingwith an in situ generated tertiary amine hydrogen chloride salt. Phenylsulfonyl chloride is the preferred sulfonating reagent for this in situreaction. For large-scale synthesis, this protocol for the preparationof hydrazonoyl chloride (Ivb) can be very convenient. Compared with theliterature-reported protocol (see Chem. Pharm. Bull. 1988, 36(2), 800),this methodology eliminates the use of the toxic carbon tetrahalide andlarge amounts of triphenylphosphine.

Hydrazonoyl sulfonates (IVc, IVd, and IVe) can be quantitativelyconverted into the corresponding hydrazonoyl chloride (IVb) by reactingwith in situ generated trialkylamine hydrogen chloride salt or cyclictertiary amine hydrogen chloride salt. This is a particularly usefulreaction for the preparation of the hydrazonoyl chloride (IVb).Hydrazonoyl chloride (IVb) formation through this in situ transformationfrom the corresponding hydrazonoyl sulfonates (IVc-e) is affected by thereactivity of the particular tertiary amine hydrogen chloride salt.Compared with the cyclic tertiary amine hydrogen chloride salt, thetrialkylamine hydrogen chloride salt is a better chlorinating agent toaffect this transformation. Consequently, duisopropylethylamine is amost preferred base for this in situ reaction. In general, hydrazonylsulfates (IVc, IVd, and IVe) are the kinectically favored products andcan be obtained by quenching the sulfonation reaction with water atlower temperatures in short reaction periods. However, the thermodynamicproduct will be hydrazonoyl chloride (IVb) exclusively if the reactionis conducted at higher temperatures for relatively longer periods oftime.

Preferably, about 1.0-1.1 equivalents of sulfonic anhydride agent areused. A weak base is used in the reaction to promote it. Pyridine (pKa5.15) is a preferred base for this reaction, even though it is notstrong enough to initiate the sulfonation reaction between sulfonylchloride and trifluoroacylated arylhydrazine (III) in the alternativeapproach detailed above. The preferred reaction temperature is from0-25° C. The reaction is usually complete in 1-2 h at 0-25° C. Thepreferred solvent is EtOAc.

Because the sulfonic anhydride is a relatively stronger sulfonatingagent compared with the corresponding sulfonyl chloride used in approachA, the sulfonation reaction between the substrate (III) carrying theelectron-withdrawing functional group(s) on its aromatic ring and thesulfonic anhydride is more regioselective. However, for the substrate(III) carrying the electron-donating functional group(s) on its aromaticring, little improvement for the regioselectivity was observed in thisalternative reaction.

This approach produces only the desired hydrazonoyl sulfonate (IVc-e),no corresponding hydrazonoyl chloride (IVb) is generated because of theabsence of a chloride source, such as tertiary amine hydrogen chloridesalt, in the reaction mixture. Therefore, it can be used as the methodto prepare pure hydrazonoyl sulfonates (IVc-e).

Acrylamides (VIb and VIc) are formed by reacting acryloyl chloride and asubstituted aniline. A base is used to promote the reaction. Preferably,1.0-2.0 equivalents of acryloyl chloride are used, more preferably about1.2-1.5 equivalents. A trialkylamine, such as triethylamine, or a cyclictertiary amine, such as N-methylmorpholine (NMM) is used as a base topromote this reaction, with NMM being preferred. A preferred solvent isEtOAc, THF, CH₂Cl₂, or acetonitrile, with EtOAc being more preferred.The reaction is preferably run at a temperature of from 0-25° C. and isusually complete in 1-4 h at 0-25° C. The product can be readilyisolated by simple aqueous work-up.

The 1,3-dipolar cycloaddition reaction of the present invention involvesreaction between an in situ generated nitrileimine (v, 1,3-dipole) and adipolarophile, such as a substituted alkene derivative (VI or VIa). Thiscycloaddition reaction regiospecifically generates the correspondingsubstituted pyrazoline (VII or VIIa). The preferred solvent for thecycloaddition reaction is EtOAc.

Generation of nitrileimine 1,3-dipole (V) can be achieved by reacting abase with its precursor (IVa-c). The preferred base is a trialkylamine,such as triethylamine or Hunig's base, or a cyclic tertiary amine, suchas NMM. Preferably, about 2-3 equivalents of base are used.

Factors like the reactivities of 1,3-dipole precursors (IVa-e) anddipolarophiles (VI or VIa) can affect the cycloaddition reaction rate.Therefore, the reaction temperature and time may be varied.Qualitatively, the order of the reactivity of the 1,3-dipole precursors(IV) is: hydrazonoyl mesylate (IVc)>hydrazonoyl bromide (IVa), tosylate(IVd), benzenesulfonate (IVe)>>hydrazonoyl chloride (IVb). The order ofthe reactivity of the dipolarophile (VI) is: alkyl acrylate (VIa)>N-arylacrylamide>N-biaryl acrylamide. When an alkyl acrylate (VIa is reactedwith hydrazonoyl bromide (IVa) or hydrazonoyl sulfonates (IVc-e)), thecycloaddition reaction can be done at room temperature in about 4-12 h.However, the cycloaddition reaction between hydrazonoyl chloride (IVb)and dipolarophiles (VI or VIa) is preferably run at elevated temperature(50-80° C.) for 12-24 h.

With a monosubstituted alkene as dipolarophile (VI), such as ethylacrylate (VIa) or N-aryl/biaryl acrylamide, the 1,3-dipolarcycloaddition reaction regiospecifically generates 5-substitutedpyrazoline (VII or VIIa) as the only product.

Step (e1): Oxidation of Pyrazoline to Pyrazole

Even though there are many oxidative dehydrogenation methodologiesreported in the literature for the preparation of substituted pyrazoles(VIII) from the corresponding pyrazolines (VII), none of them can bepractically employed on a large-scale synthesis. Thus, the presentinvention involves two novel methods for the oxidation of thecycloaddition product pyrazoline (VII or VIIa) to pyrazole (VIII orVIIIa).

This process involves a reaction between a substituted pyrazoline (VIIor VIIa) and N-chlorosuccinimide (NCS). The electrophilic chlorinatedpyrazoline intermediate undergoes an in situ dehydrohalogenation toproduce the corresponding pyrazole (VIII or VIIIa). Preferably, about1.0-1.1 equivalents of N-chlorosucinimide (NCS) are used in thereaction. Excess NCS results in the undesired chlorination of thearomatic ring. Thus, it is preferable to minimize the amount of NCSused.

The preferred solvent for this aromatization reaction is THF. A polarsolvent such as DMF was found to result in the formation of the aromaticring chlorination by-product. The reaction is preferable run at 0-25° C.At room temperature, the reaction is usually complete in about 1-2 h.

Aromatic ring chlorination by-product is observed when the substratepyrazoline (VII or VIIa) contains an electron-donating functionalgroup(s) on its aromatic ring. Therefore, this method should be usedonly when the substrate pyrazoline (VII or VIIa) is substituted withelectron-withdrawing functional group(s).

The oxidation product, pyrazole (VIII or VIIIa), can be isolated fromthe reaction mixture through routine aqueous work-up. The succinimidegenerated from the reaction dissolves in water. Therefore, it can beextracted readily into the aqueous layer of the work-up mixture.

This process involves a reaction between a substituted pyrazoline (VIIor VIIa) and oxygen in air under basic conditions. The enolate of5-carboyxlate/carbamoyl substituted pyrazoline (VII or VIIa) is oxidizedby oxygen in air to produce the corresponding pyrazole (VIII or VIIIa).Preferably, oxygen in air, 7% oxygen in nitrogen, or pure oxygen as isused as the oxidant. The preferred oxygen source of large scale reactionis oxygen in air (22%) or oxygen in nitrogen (7%). A relatively strongbase is used to generate the corresponding substituted pyrazoline (VIIor VIIa) enolate. The preferred base is potassium tert-butoxide. Apolar, aprotic solvent is preferred. The most preferred solvent is DMFor DMAC (N,N-dimethylaminoacetamide). The reaction is run from −25-25°C., with the preferred temperature range being −15-5° C. The reaction isusually complete in 1-8 h at −15-5° C. The reaction time is alsodependent on the oxygen source employed.

This protocol is applicable to the oxidation of all the pyrazolines (VIIor VIIa), no matter what their aromatic substitution patterns are.Therefore, it can be used for pyrazolines with electron-donatingfunctional group(s) on their aromatic rings.

The Pd(0) catalyst used in the Suzuki coupling is preferably Pd(PPh₃)₄.About 1-5% equivalents of the catalyst are used to catalyze thiscoupling reaction with 2% being preferred. About 1.0-1.5 equivalents ofan arylboronic acid are used, with 1-2 equivalents being preferred. Abase is used to promote the Suzuki coupling reaction. The preferred baseis an inorganic salt, such as potassium carbonate or sodium carbonate.The most preferred base is sodium carbonate. A mixed solvent system isused for this Suzuki coupling reaction. The preferred solvent system istoluene/ethanol/water (2-4:1:1 v/v/v). Preferably the reaction is run atelevated temperature, the preferred temperature range being 70-80° C.Usually, the reaction is complete in 4-20 h at 70-80° C.

A selected class of oxidation reagents can be used to oxidize thethiomethyl (—SMe) functionality to the corresponding sulfone (—SO₂Me).The preferred oxidants are mCPBA and Oxone®. About 2-10 equivalents ofmCPBA or Oxone® are used to do this oxidation reaction, with 2-5eqivalents being preferred. Several different solvents or solventsystems are used for this oxidation reaction. The choice for the solventor solvent system is dependent on the oxidant used for the reaction.With mCPBA as an oxidant, ethyl acetate (EtOAc) is preferred. WithOxone® as an oxidant, the preferred solvent system is a mixture ofacetone and water in a volume ratio of one to one. The oxidationreaction can be run at 25-50° C., depending on the oxidant used for thereaction. With mCPBA as an oxidant, the oxidation reaction can be run atroom temperature (20-25° C.). But, when Oxone® is used as an oxidant,the reaction is run at elevated temperature, the preferred temperaturerange being 40-50° C. Generally, the reaction is complete in 5-20 h at20-50° C.

Reduction of the cyano group to a benzylamine can be achieved with achemical reducing reagent, such as NaBH₄, or via Pd(0) catalyzedhydrogenation. The preferred reduction procedure is palladium catalyzedhydrogenation. About 1-2% (weight) of the palladium on charcoal (5% or10%) can be used. The preferred solvent for the hydrogenation reactionis ethanol. The reaction is normally run at 20-25° C. Usually, thereaction is complete in 4-6 h at 20-25° C. under 50-55 psig hydrogenpressure. When the reaction is conducted in the existence of an acid,such as hydrochloric acid (HCl), the corresponding salt, such asbenzylamine hydrochloride salt, is obtained. When the reduction reactionis conducted in the existence of an electrophile that is used for the insitu protection of the generated benzylamine, such as di-tert-butyldicarbonate (Boc₂O) or trifluoroacetic acid anhydride (TFAA), thecorresponding protected benzylamine (Boc or TFA) is obtained.

Converting of the ortho fluoro/cyano substituents to the correspondingaminobenzisoxazole functionality in ring D is achieved in two ways. Thefirst method involves a two-step sequential reaction. Substitution ofthe fluoro functionality ortho to the cyano group with an acetone oximein the existence of a base, such as potassium tert-butoxide or NaH, inanhydrous solvent, such as THF or DMF, generates the correspondingacetone oxime substituted intermediate. This intermediate issubsequently converted into the desired aminobenzisoxazole ring bytreating with an acid. About 2-4 equivalents of acetone oxime are usedfor this substituted reaction. The preferred base is sodium hydride. Theanhydrous DMF is the preferred solvent. At 0-25° C., the substutionreaction is complete in 1-2 h.

The second method involves a one-step reaction between fluoro/cyanosubstituted substrate and an acetohydroxamic acid. Potassium carbonateis preferably used as the base to promote the reaction. Normally, 5-10equivalents potassium carbonate is used for the reaction. The preferredsolvent system is a mixture of DMF and water in a volume ratio 10-15to 1. The reaction is conducted at 20-30° C. At such a temperaturerange, the reaction is usually complete in 10-15 h.

The Boc protection group is removed to release the correspondingbenzylamine by treating the N-Boc benzylamine with an acid. The typicalacid used for this deprotection reaction is hydrochloric acid (HCl). Thepreferred HCl form is 5 to 6 N HCl solution in isopropyl alcohol (IPA).By treatment the corresponding Boc protected benzylamine with excessamount of HCl solution in isopropyl alcohol (IPA) at 20-25° C. forseveral hours, the corresponding benzylamine hydrochloride salt isgenerated. Normally, 1-5 equivalents of HCl solution in isopropylalcohol is used.

Trifluoroacetic acid (TFA) is also useful to remove the Boc group. Theresulting deprotection product is the corresponding benzylaminetrifluoroacetic acid salt. Normally, the excess amount oftrifluoroacetic acid is used. The deprotection reaction is also run at20-25° C. The reaction is usually complete in 2-10 h.

Trifluoroacetyl protection group of benzylamine is removed by treatingthe corresponding TFA protected benzylamine with an inorganic base, suchas sodium hydroxide or potassium hydroxide, or an inorganic salt, suchas potassium carbonate. The preferred base is potassium carbonate.Normally, 1 to 4 equivalents of potassium carbonate are used for thereaction. Alkyl alcohol, such as methanol or ethanol, is used assolvent. The reaction is run at 20-60° C. The preferred temperaturerange is 50-60° C. Normally, the reaction is complete in 2 to 10 h at50-60° C. The deprotection reaction under such a condition generates thecorresponding benzylamine as a free base.

Removal of the tert-butyl group to release the corresponding sulfamideis also conducted in an acidic condition. The preferred acid used forthis reaction is a 5 to 6 N hydrochloric acid solution in isopropylalcohol. Normally, an excess of hydrogen chloride is employed. Theisopropyl alcohol, which makes hydrogen chloride solution, is also areaction solvent. The reaction is usually run at an elevatedtemperature. The preferred temperature range is 70-80° C. The reactionis usually complete in 30 to 50 hours at 70-80° C.

Other features of the invention will become apparent in the course ofthe following descriptions of examplary embodiments which are given forillustration of the invention and are not intended to be limitingthereof.

EXAMPLES Example 1

1-(3-Cyano)phenyl-2-(trifluoroacetyl)hydrazine (1)

A solution of 3-cyanobenzenehydrazine (107 g, 0.8 mol) in anhydrous THF(800 mL) was treated dropwise with a solution of trifluoroaceticanhydride (TFAA, 168.0 g, 113 mL, 0.8 mol, 1.0 equiv) in anhydrous THF(150 mL) at 5-7° C. under N₂. The resulting reaction mixture was thenstirred at 5-15° C. for an additional 1 h. When HPLC showed the reactionwas deemed complete, 700-750 mL of THF was removed in vacuo. Theresidual slurry was then treated with heptanes (1400 mL) with goodstirring. The resulting solids were aged for 1 h at room temperature andthen cooled to 0-5° C. in an ice-bath for an additional 1 h. The solidswere collected by filtration, washed with heptanes (2×300 mL), and driedat 40-50° C. in vacuo for 12 h to afford the crude desired1-(3-cyano)phenyl-2-(trifluoroacetyl)hydrazine (1, 178 g, 215 gtheoretical, 83%), which was found to be essentially pure to do thefollowing reaction without further purification. The analytically pureproduct (1) was obtained from recrystalization of the crude materialobtained above from EtOAc/heptanes. For 1: CIMS m/z 228 (M⁺−H,C₉H₆F₃N₃O).

Example 2

2,2,2-Trifluoro-N-(3-cyano)phenylethanehydrazonoyl chloride (2). MethodA

A suspension of 1-(3-cyano)phenyl-2-(trifluoroacetyl)hydrazine (1, 2.6g, 11.3 mmol) in acetonitrile (20 mL) was treated with CCl₄ (3.48 g, 2.2mL, 22.6 mmol, 2.0 equiv) and PPh₃ (4.4 g, 17.0 mmol, 1.5 equiv) at 25°C. under N₂. The resulting reaction mixture, which was turned into aclear solution after 10-20 min at room temperature, was then stirred at25° C. for 14 h. When the HPLC showed that the reaction was deemedcomplete, the solvent was removed in vacuo. The oily residue wasdirectly purified by the flash column chromatography (SiO₂, 5-20%EtoAc-hexanes gradient elution) to afford2,2,2-trifluoro-N-(3-cyanophenyl)ethanehydrazonoyl chloride (2, 2.3 g,2.85 g theoretical, 81%) as off-white solids. For 2: CIMS m/z 246/248(M⁺−H, C₉H₅ClF₃N₃).

Example 3

2,2,2-Trifluoro-N-(3-cyano)phenylethanehydrazonoyl chloride (2). MethodB

A solution of 1-(3-cyano)phenyl-2-(trifluoroacetyl)hydrazine (1, 2.5 g,10.9 mmol) in ethyl acetate (20 mL) was treated with methanesulfonylchloride (1.50 g, 1.01 mL, 13.1 mmol, 1.2 equiv) at 0° C. under N₂, andthe resulting reaction was added dropwise triethylamine (TEA, 1.65 g,2.34 mL, 16.4 mmol, 1.5 equiv) at 0° C. under N₂. The reaction mixturewas then stirred at 0° C. for 10 min before being gradually warmed toroom temperature for 3 h. When the HPLC showed that the reaction wasdeemed complete, the reaction mixture was treated with water (20 mL) andEtOAc (20 mL). The two layers were separated, and the aqueous layer wasextracted with EtOAc (20 mL). The combined organic extracts were washedwith water (2×20 mL) and saturated NaCl aqueous solution (20 mL), driedover MgSO₄, and concentrated in vacuo. Flash column chromatography(SiO₂, 10-25% EtOAc-hexanes gradient elution) afforded2,2,2-trifluoro-N-(3-cyanophenyl)ethane-hydrazonoyl chloride (2, 2.07 g,2.47 g theoretical, 83.2%) as white solids, which was found to beidentical with the material obtained from method A detailed above inevery comparable aspect.

Example 4

2,2,2-Trifluoro-N-(3-cyanophenyl)ethanehydrazonoyl bromide (3)

A suspension of 1-(3-cyano)phenyl-2-(trifluoroacetyl)hydrazine (1, 2.29g, 10.0 mmol) in acetonitrile (20 mL) was treated with CBr₄ (6.633 g, 20mmol, 2.0 equiv) and PPh₃ (5.25 g, 20 mmol, 2.0 equiv) at 25° C. underN₂. The resulting reaction mixture, which was turned into a clearsolution after 10-20 min at room temperature, was then stirred at 25° C.for 20 h. When the HPLC showed that the reaction was deemed complete,the solvent was removed in vacuo. The oily residue was directly purifiedby the flash column chromatography (SiO₂, 5-20% EtOAc-hexanes gradientelution) to afford 2,2,2-trifluoro-N-(3-cyanophenyl)ethanehydrazonoylbromide (3, 2.39 g, 2.92 g theoretical, 82%) as pale-yellow solids. For3: CIMS m/z 291/293 (M⁺−H, C₉H₅BrF₃N₃).

Example 5

2,2,2-Trifluoro-N-(3-cyano)phenylethanehydrazonoyl mesylate (4)

A solution of 1-(3-cyano)phenyl-2-(trifluoroacetyl)hydrazine (1, 229 mg,1.0 mmol) in ethyl acetate (3.0 mL) was treated with methanesulfonylchloride (172 mg, 116 μL, 1.5 mmol, 1.5 equiv) at 0° C. under N₂, andthe resulting reaction was added dropwise N-methylmorpholine (NMM, 121mg, 132 μL, 1.2 mmol, 1.2 equiv) at 0° C. The reaction mixture was thenstirred at 0° C. for 10 min before being gradually warmed to roomtemperature for 3-4 h. When the HPLC showed that the reaction was deemedcomplete, the reaction mixture was treated with water (5 mL) and EtOAc(5 mL). The two layers were separated, and the aqueous layer wasextracted with EtOAc (5 mL). The combined organic extracts were washedwith water (2×10 mL) and saturated NaCl aqueous solution (5 mL), driedover MgSO₄, and concentrated in vacuo. Flash column chromatography(SiO₂, 10-25% EtOAc-hexanes gradient elution) afforded2,2,2-trifluoro-N-(3-cyanophenyl)ethane- hydrazonoyl mesylate (4, 252mg, 311 mg theoretical, 81%) as white solids. For 4: CIMS m/z 306 (M⁺−H,C₁₀H₈F₃N₃O₃S).

Example 6

2,2,2-Trifluoro-N-(3-cyano)phenylethanehydrazonoyl tosylate (5). MethodA

A solution of 1-(3-cyano)phenyl-2-(trifluoroacetyl)hydrazine (1, 22.9 g,0.1 mol) in ethyl acetate (180 mL) was treated with p-toluenesulfonylchloride (24.8 g, 0.13 mol, 1.3 equiv) at 0° C. under N₂, and theresulting reaction was added dropwise a solution of N-methylmorpholine(NMM, 11.11 g, 12.1 mL, 0.11 mmol, 1.1 equiv) at 0° C. under N₂. Thereaction mixture was then stirred at 0° C. for 10 min before beinggradually warmed to room temperature for 3-4 h. When the HPLC showedthat the reaction had a greater than 95% conversion, the reactionmixture was treated with water (200 mL) and EtOAc (300 mL). Theresulting mixture was stirred at room temperature for 30 min. The twolayers were then separated, and the aqueous layer was extracted withEtOAc (100 mL). The combined organic extracts were washed with water(2×100 mL) and saturated NaCl aqueous solution (100 mL), dried overMgSO₄, and concentrated in vacuo. The residual ethyl acetate solution(100 mL) was added heptanes (400 mL), and the resulting mixture wasstirred at room temperature for 1 h to precipitate the desired tosylate.The solids were collected by filtration, washed with EtOAc-hexanes (1:5,2×50 mL) and dried in vacuo. The crude desired2,2,2-trifluoro-N-(3-cyanophenyl)ethanehydrazonoyl tosylate (5, 31.03 g,38.3 g theoretical, 81%) was obtained as pale-yellow solids, which wasfound to be >96% pure by HPLC. The only observable impurity (3-4%) wasfound to be the corresponding iminoyl chloride (2), which will notaffect the following cycloaddition reaction. The analytically pureproduct (5) was obtained from flash column chromatography (SiO₂, 5-20%EtOAc-hexanes gradient elution) purification or recrystalization(EtOAc/heptanes) of the crude 5 obtained above. For 5: CIMS m/z 382(M⁺−H, C₁₆H₁₂F₃N₃O₃S).

Example 7

2,2,2-Trifluoro-N-(3-cyano)phenylethanehydrazonoyl tosylate (5). MethodB

A solution of 1-(3-cyano)phenyl-2-(trifluoroacetyl)hydrazine (1, 229 mg,1.0 mmol) in ethyl acetate (3.0 mL) was treated with p-toluenesulfonylanhydride (97% pure, 370 mg, 1.1 mmol, 1.1 equiv) at 0° C. under N₂, andthe resulting mixture was treated dropwise with pyridine (118.7 mg, 121μL, 1.5 mmol, 1.5 equiv) at 0° C. under N₂. The reaction mixture wasthen gradually warmed to room temperature for 2 h. When HPLC showed thereaction was deemed complete, the reaction mixture was treated withwater (10 mL) and EtOAc (10 mL). The two layers were separated, and theaqueous layer was extracted with EtOAc (10 mL). The combined organicextracts were washed with water (2×10 mL) and saturated NaCl aqueoussolution (10 mL), dried over MgSO₄, and concentrated in vacuo. The crudedesired product (5, 375 mg, 383 mg theoretical, 98%), which was found tobe identical with the material obtained from method A in everycomparable aspect and to be essentially pure to do the followingcycloaddition reaction without further purification.

Example 8

Ethyl 1-(3-cyano)phenyl-3-trifluoramethylpyrazoline-5-carboxylate (6).Method A

A suspension of 2,2,2-trifluoro-N-(3-cyanophenyl)ethanehydrazonoylbromide (3, 514 mg, 1.76 mmol) in toluene (5 mL) was treated with ethylacrylate (352 mg, 373 μL, 3.52 mmol, 2.0 equiv) at 0° C. under N₂, andthe resulting reaction mixture was treated dropwise with triethylamine(TEA, 267 mg, 377 μL, 2.64 mmol, 1.5 equiv) at 0° C. under N₂. Thereaction mixture was then gradually warmed to room temperature for 10 h.When the HPLC showed the reaction was deemed complete, the reactionmixture was directly purified by flash column chromatography (SiO₂,0-20% EtOAc-hexanes gradient elution) to afford ethyl1-(3-cyano)phenyl-3-trifluoromethylpyrazoline-5-carboxylate (6, 504 mg,547 mg theoretical, 92%) as the pale yellow oil, which was graduallysolidified upon standing at room temperature. For 6: CIMS m/z 312 (M⁺H,C₁₄H₁₂F₃N₃O₂).

Example 9

Ethyl 1-(3-cyano)phenyl-3-trifluoromethylpyrazoline-5-carboxylate (6).Method B

A suspension of 2,2,2-trifluoro-N-(3-cyanophenyl)ethanehydrazonoylmesylate (4, 31 mg, 0.1 mmol) in toluene (1 mL) was treated with ethylacrylate (20 mg, 22 μL, 0.2 mmol, 2.0 equiv) at 0° C. under N₂, and theresulting reaction mixture was treated dropwise with triethylamine (TEA,15 mg, 22 uL, 0.15 mmol, 1.5 equiv) at 0° C. under N₂. The reactionmixture was then gradually warmed to room temperature for 4 h. When theHPLC showed the reaction was deemed complete, the reaction mixture wasdirectly purified by flash column chromatography (SiO₂, 0-20%EtOAc-hexanes gradient elution) to afford ethyl1-(3-cyano)phenyl-3-trifluoromethylpyrazoline-5-carboxylate (6, 18 mg,31.1 mg theoretical, 58%) as the pale yellow oil, which was found to beidentical with the material obtained from method A in every comparableaspect and was gradually solidified upon standing at room temperature.

Example 10

Ethyl 1-(3-cyano)phenyl-3-trifluoromethylpyrazoline-5-carboxylate (6).Method C

A suspension of 2,2,2-trifluoro-N-(3-cyanophenyl)ethanehydrazonoyltosylate (5, 79 mg, 0.2 mmol) in toluene (2 mL) was treated with ethylacrylate (40 mg, 44 μL, 0.4 mmol, 2.0 equiv) at 0° C. under N₂, and theresulting reaction mixture was treated dropwise with triethylamine (TEA,30 mg, 44 μL, 0.3 mmol, 1.5 equiv) at 0° C. under N₂. The reactionmixture was then gradually warmed to room temperature for 10 h. When theHPLC showed the reaction was deemed complete, the reaction mixture wasdirectly purified by flash column chromatography (SiO₂, 0-20%EtOAc-hexanes gradient elution) to afford ethyl1-(3-cyano)phenyl-3-trifluoromethylpyrazoline-5-carboxylate (6, 53 mg,62.2 mg theoretical, 85%) as the pale yellow oil, which was found to beidentical with the material obtained from method A and B in everycomparable aspect and was gradually solidified upon standing at roomtemperature.

Example 11

Ethyl 1-(3-cyano)phenyl-3-trifluoromethylpyrazoline-5-carboxylate (6).Method D

A suspension of 2,2,2-trifluoro-N-(3-cyanophenyl)ethanehydrazonoylchloride (2, 124 mg, 0.5 mmol) in toluene (2 mL) was treated with ethylacrylate (100 mg, 108 μL, 1.0 mmol, 2.0 equiv) at 0° C. under N₂, andthe resulting reaction mixture was treated dropwise with triethylamine(TEA, 76 mg, 108 μL, 0.75 mmol, 1.5 equiv) at 0° C. under N₂. Thereaction mixture was then gradually warmed to room temperature for 50 h.The HPLC showed that 60% of the starting material (2) was converted intothe corresponding cycloaddition product (6) and the rest of the 40% ofstarting material (2) was still existed in the reaction mixture. Thereaction mixture was directly purified by flash column chromatography(SiO₂, 0-20% EtOAc-hexanes gradient elution) to afford ethyl1-(3-cyano)phenyl-3-trifluoromethylpyrazoline-5-carboxylate (6, 78 mg,156 mg theoretical, 50%) as the pale yellow oil, which was graduallysolidified upon standing at room temperature and was found to beidentical with the material obtained from method A, B and C detailedabove in every comparable aspect.

Example 12

Ethyl 1-(3-cyano)phenyl-3-trifluoromethylpyrazole-5-carboxylate (7)

A solution of ethyl1-(3-cyano)phenyl-3-trifluoromethylpyrazoline-5-carboxylate (6, 84 mg,0.27 mmol) in THF (2 mL) was treated with N-chlorosuccinimide (NCS, 40mg, 0.3 mmol, 1.1 equiv) at 0° C., and the resulting reaction mixturewas gradually warmed to room temperature for 1 h. When the HPLC and TLCshowed the reaction was deemed complete, the reaction mixture wastreated with water (10 mL) and tert-butyl methyl ether (TBME, 10 mL).The two layers were then separated, and the aqueous layer was extractedwith TBME (5 mL). The combined organic extracts were washed with water(2×5 mL) and saturated NaCl aqueous solution (10 mL), dried over MgSO₄,and concentrated in vacuo. The crude ethyl1-(3-cyano)phenyl-3-trifluoromethylpyrazole-5-carboxylate (7, 79 mg, 83mg theoretical, 95%) was obtained as white solids, which was found tobe >99% pure by HPLC and can be used in the following hydrolysisreaction without further purification. The analytically pure product (7)was obtained from flash column chromatography (SiO₂, 10-30%EtOAc/hexanes gradient elution) purification or recrystalization(EtOAc/hexanes) of the crude 7 obtained above. For 7: CIMS m/z 310(M⁺+H, C₁₄H₁₀F₃N₃O₂).

Example 13

1-(3-Cyano)phenyl-3-trifluoromethylpyrazole-5-carboxylic acid (8)

A solution of ethyl1-(3-cyano)phenyl-3-trifluoromethylpyrazole-5-carboxylate (7, 800 mg,2.58 mmol) in THF-MeOH-H₂O (3:1:1 v/v, 6 mL) was treated with lithiumhydroxide monohydrate (LiOH-H₂O, 155 mg, 3.88 mmol, 1.5 equiv) at roomtemperature, and the resulting reaction mixture was stirred at roomtemperature for 10 h. When HPLC and TLC showed that the reaction wasdeemed complete, the solvent was removed in vacuo, and the residue wastreated with water (10 mL) and EtOAc (10 mL). The two layers wereseparated, and the aqueous layer was extracted with EtOAc (5 mL). Thecombined organic extracts were discarded. The aqueous layer was thenacidified with 4 N aqueous HCl to pH 3.0 before being extracted withEtOAc (2×10 mL). The combined organic extracts were washed with H₂O (10mL) and saturated NaCl aqueous solution (10 mL), dried over MgSO₄, andconcentrated in vacuo. The crude1-(3-cyano)phenyl-3-trifluoromethylpyrazole-5-carboxylic acid (8, 605mg, 725 mg theoretical, 84%) was obtained as pale-yellow solids, whichwas found to be identical with the material obtained from anothertotally different synthetic method in every comparable aspect and tobe >99% pure by HPLC. This crude product can be directly used in thefollowing reaction without further purification. The analytically pureproduct (8) was obtained from flash column chromatography (SiO₂, 10-50%EtOAc/hexanes gradient elution) purification or recrystalization(EtOAc/hexanes) of the crude 8 obtained above. For 8: CIMS m/z 280(M⁺−H, C₁₂H₆F₃N₃O₂).

Example 14

N-(4-Bromo-2-fluoro)phenyl acrylamide (9)

A solution of 4-bromo-2-fluoroaniline (19.0 g, 0.1 mol) in CH₂Cl₂ (100mL) was treated with acryloyl chloride (12.35 g, 11.1 mL, 0.13 mmol, 1.3equiv) at 0° C. under N₂, and the resulting mixture was treated dropwisewith a solution of triethylamine (TEA, 15.15 g, 21.6 mL, 0.15 mmol, 1.5equiv) in CH₂Cl₂ (50 mL) at 0° C. under N₂. The reaction mixture wasthen gradually warmed to room temperature and stirred at roomtemperature for 2 h before being quenched with water (300 mL). Thesolids precipitated from the mixture were collected by filtration,washed with water (100 mL) and TBME-hexane (1:2 v/v, 2×100 mL), anddried in vacuo at 40-45° C. for 12 h to afford the first batch of thecrude desired N-(4-bromo-2-fluoro)phenyl acrylamide (9, 17.8 g, 24.4 gtheoretical, 73%) as grey solids, which was found to be >99% pure byHPLC. The two layers of the filtrates were then separated, and theaqueous layer was extracted with CH₂Cl₂ (2×100 mL). The combined organicextracts were washed with H₂O (100 mL) and saturated aqueous NaClsolution (100 mL), dried over MgSO₄, and concentrated in vacuo to affordthe second batch of the crude desired product (9, 4.3 g, 24.4 gtheoretical, 17.6%; total 90% yield) as off-white solids, which wasfound to be pure enough to do the following reaction without furtherpurification. The analytically pure product (9) was obtained from directrecrystalization of the crude 9 obtained above from EtOAc/heptanes. For9: CIMS m/z 242/244 (M⁺−H, C₉H₇BrFNO).

Example 15

5-(4-Brono-2-fluoro)phenylcarbamoyl-1-(3-cyano)phenyl-3-trifluoromethyl-pyrazoline(10)

A suspension of 1-(3-cyano)phenyl-2-(trifluoroacetyl)hydrazine (1, 22.9g, 0.1 mol) in EtOAc (200 mL) was treated with benzenesulfonyl chloride(18.55 g, 13.4 mL, 0.105 mol, 1.05 equiv), and the resulting mixture wastreated dropwise with N-methylmorpholine (NMM, 11.11 g, 12.1 mL, 0.11mol, 1.1 equiv) at 0° C. under N₂. The resulting reaction mixture wasstirred at 0-5° C. for 30 min before being gradually warmed up to 25° C.for 2 h. When HPLC showed that the transformation of starting materialinto the corresponding2,2,2-trifluoro-N-(3-cyanophenyl)ethanehydrazonoyl chloride (2) wasdeemed complete, the reaction mixture was treated withN-(4-bromo-2-fluoro)phenyl acrylamide (9, 22.4 g, 0.092 mol, 0.92 equiv)and triethylamine (30.3 g, 43.3 mL, 0.3 mol, 3.0 equiv) at 25° C. underN₂. The resulting reaction mixture was subsequently warmed up to gentlereflux (80° C.) for 18 h. When HPLC showed that the cycloadditionreaction was deemed complete, the reaction mixture was cooled down toroom temperature before being treated with H₂O (200 mL) and EtOAc (200mL). The mixture was stirred at room temperature for 30 min. The twolayers were separated. The aqueous layer was extracted with EtOAc (100mL). The combined organic extracts were washed with H₂O (2×200 mL) andsaturated NaCl aqueous solution (200 mL), dried over MgSO₄, andconcentrated in vacuo to leave a slurry of the crude cycloadditionproduct (10) in about 100 mL of EtOAc. The residual slurry was thentreated with heptanes (400 mL), and the resulting mixture was stirred atroom temperature for 1 h before being cooled down to 0° C. for anadditional 2 h. The solids were collected by filtration, washed withheptanes (2×100 mL), and dried in vacuo at 40-45° C. for 12 h to affordthe crude desired5-(4-bromo-2-fluoro)phenylcarbamoyl-1-(3-cyano)phenyl-3-trifluoromethyl-pyrazoline(10, 37.9 g, 41.86 g theoretical, 90.5%), which was found to be pureenough to do the following reaction without further purification. Theanalytically pure product (10) was obtained from recrystalization of thecrude product obtained above from EtOAc-heptanes. For 10: CIMS m/z453/455 (M⁺−H, C₁₈H₁₁F₄BrN₄O).

Example 16

5-(4-Bromo-2-fluoro)phenylcarbamyl-1-(3-cyano)phonyl-3-trifluoromethyl-pyrazole(11)

A suspension of5-(4-bromo-2-fluoro)phenylcarbamoyl-1-(3-cyano)phenyl-3-trifluoromethylpyrazoline(10, 10.6 g, 23.3 mmol) in THF (100 mL) was treated withN-chlorosuccinimide (NCS, 3.17 g, 23.8 mmol, 1.05 equiv) at 0-5° C., andthe resulting reaction mixture was gradually warmed to room temperaturefor 2 h. When the HPLC and TLC showed the reaction was deemed complete,the reaction mixture was treated with water (100 mL) and THF (100 mL).The two layers were separated, and the aqueous layer was extracted withEtOAc (100 mL). The combined organic extracts were washed with water(2×100 mL) and saturated NaCl aqueous solution (100 mL), dried overMgSO₄, and concentrated in vacuo. The residual slurry of the crudeproduct in THF/EtOAc (about 50 mL) was treated with heptanes (200 mL),and the resulting mixture was stirred at room temperature for 1 h. Thesolids were collected by filtration, washed with heptanes (2×50 mL), anddried in vacuo at 40-45° C. for 12 h to afford the crude5-(4-bromo-2-fluoro)phenylcarbamoyl-1-(3-cyano)phenyl-3-trifluoromethyl-pyrazole(11, 9.99 g, 10.55 g theoretical, 95%), which was found to be pureenough to do the following reaction without further purification. Theanalytically pure product (11) was obtained from recrystalization of thecrude product obtained above from EtOAc/heptanes. For 11: CIMS m/z451/453 (M⁺−H, C₁₈H₉F₄BrN₄O).

Example 17

N-[2-Fluoro-4-(2-methylsulfonyl)phenyl]phenyl acrylamide (12)

A solution of 2-fluoro-4-(2-methylsulfonyl)phenylanaline hydrochloridesalt (60.3 g, 0.2 mol) in EtOAc (400 mL) was treated with NMM (50.5 g,54.9 mL, 0.5 mol, 2.5 equiv) at 0° C. under N₂, and the resultingmixture was treated dropwise with a solution of acryloyl chloride (32.58g, 28.6 mL, 0.13 mmol, 1.8 equiv) at 0° C. under N₂. The reactionmixture was then stirred at 0-5° C. for 1 h before being quenched withwater (400 mL). The solids precipitated from the mixture were collectedby filtration, washed with water (100 mL) and EtOAc-hexane (1:3 v/v,2×100 mL), and dried in vacuo at 40-45° C. for 12 h to afford the firstbatch of the crude N-[2-fluoro-4-(2-methylsulfonyl)phenyl]phenylacrylamide (12, 32.6 g, 63.8 g theoretical, 51.1%) as white powder,which was found to be >99.5% pure by HPLC. The two layers of thefiltrates were then separated, and the aqueous layer was extracted withEtOAc (150 mL). The combined organic extracts were washed with H₂O(2×100 mL) and saturated NaCl aqueous solution (100 mL), dried overMgSO₄, and concentrated in vacuo. The residual slurry (about 50 mL) wasthen treated with heptanes (400 mL). The mixture was stirred at roomtemperature for 30 min before being filtrated. The collected solids werewashed with heptanes (2×50 mL), and dried in vacuo at 40-45° C. for 12 hto afford the second batch of the crudeN-[2-fluoro-4-(2-methylsulfonyl)phenyl)]phenyl acrylamide (12, 23.2 g,63.8 g theoretical, 36.4%) as white powder, which was found to be >99.5%pure by HPLC. The crude product (55.8 g, 63.8 g theoretical, total 87.5%yield) was found to be pure enough to do the following reaction withoutfurther purification. The analytically pure product (12) was obtainedfrom recrystalization of the crude product obtained above fromEtOAc/heptanes. For 12: CIMS m/z 318 (M⁺−H, C₁₆H₁₄FNO₃S).

Example 18

1-(3-Cyano)phenyl-5-[2-fluoro-4-(2-methylsulfonyl)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazoline(13)

A suspension of 1-(3-cyano)phenyl-2-(trifluoroacetyl)hydrazine (1, 6.87g, 0.03 mol) in EtOAc (60 mL) was treated with methanesulfonyl chloride(3.78 g, 2.55 mL, 0.033 mol, 1.1 equiv), and the resulting mixture wastreated dropwise with triethylamine (TEA, 3.64 g, 5.2 mL, 0.036 mol, 1.2equiv) at 0-5° C. under N₂. The resulting reaction mixture was stirredat 0-5° C. for 30 min before being gradually warmed up to 25° C. for 2h. When HPLC showed that the transformation of starting material (1)into the corresponding2,2,2-trifluoro-N-(3-cyanophenyl)ethanehydrazonoyl chloride (2) wasdeemed complete, the reaction mixture was treated withN-[2-fluoro-4-(2-methylsulfonyl)phenyl]phenyl acrylamide (10, 9.28 g,0.0291 mol, 0.97 equiv) and triethylamine (TEA, 9.09 g, 13 mL, 0.09 mol,3.0 equiv) at 25° C. under N₂. The resulting reaction mixture wassubsequently warmed up to gentle reflux (80° C.) for 24 h. When HPLCshowed that the cycloaddition reaction was deemed complete, the reactionmixture was cooled down to room temperature before being treated withH₂O (100 mL) and EtOAc (100 mL). The mixture was stirred at roomtemperature for 30 min. The two layers were separated. The aqueous layerwas extracted with EtOAc (50 mL). The combined organic extracts werewashed with H₂O (2×50 mL) and saturated NaCl aqueous solution (50 mL),dried over MgSO₄, and concentrated in vacuo to leave a slurry of thecrude cycloaddition product (13) in about 40 mL of EtOAc. The residualslurry was then treated with heptanes (200 mL), and the resultingmixture was stirred at room temperature for 1 h before being cooled downto 0° C. for an additional 2 h. The solids were collected by filtration,washed with heptanes (2×50 mL), and dried in vacuo at 40-45° C. for 12 hto afford the crude desired1-(3-cyano)phenyl-5-[2-fluoro-4-(2-(methsulfonyl)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazoline(13, 12.40 g, 15.9 g theoretical, 78%), which was found to be pureenough to do the following reaction without further purification. Theanalytically pure product (13) was obtained from recrystalization of thecrude product obtained above from EtOAc/heptanes. For 13: CIMS m/z 529(M⁺−H, C₂₅H₁₈F₄N₄O₃S).

Example 19

1-(3-Cyano)phenyl-5-[2-fluoro-4-(2-methylsulfonyl)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazole(14)

A suspention of1-(3-cyano)phenyl-5-[2-fluoro-4-(2-methylsulfonyl)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazoline(13, 8.8 g, 16.6 mmol) in THF (60 mL) was treated withN-chlorosuccinimide (NCS, 2.33 g, 17.4 mmol, 1.05 equiv) at 0-5° C., andthe resulting reaction mixture was stirred at 0-5° C. for 30 min beforebeing warmed to 25° C. for 2 h. When HPLC and TLC showed that thereaction was deemed complete, most of the solvent (THF) was removed invacuo. The residue was then treated with H₂O (100 mL) and EtOAc (200mL), and the resulting solution was stirred at room temperature for 10min. The two layers were separated, and the aqueous layer was extractedwith EtOAc (50 mL). The combined organic extracts were washed with H₂O(2×100 mL) and saturated aqueous NaCl (50 mL), dried over MgSO₄, andconcentrated in vacuo. The residual slurry of the crude product (14) inTHF/EtOAc (40 mL) was titrated with heptanes (200 mL) to precipitate thecrude desired oxidation product (14). The solids were collected byfiltration, washed with heptanes (2×50 mL), and dried at 40-45° C. for12 h to afford the crude desired1-(3-cyano)phenyl-5-[2-fluoro-4-(2-methylsulfonyl)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazole(14, 8.4 g, 8.76 g theoretical, 95.9%), which was found to be pureenough to do the following reaction without further purification. Theanalytically pure product (14) was obtained from recrystalization of thecrude product obtained above from EtOAc/heptanes. For 14: CIMS m/z 527(M⁺−H, C₂₅H₁₆F₄N₄O₃S).

Example 20

1-[3-((N-tert-Butoxy)carbonyl)aminomethyl]phenyl-2-(trifluoroacetyl)hydrazine (15)

A solution of 1-(3-cyano)phenyl-2-(trifluoroacetyl)hydrazine (1, 1.20Kg, 5.24 mol) and di-tert-butyl dicarbonate (Boc₂O, 1.37 Kg, 6.29 mol,1.2 equiv) in methanol (10 L) was introduced into a 5-gallon pressurereactor (Parr model SS 1996) containing 5% palladium on carbon (50% wetcatalyst, 0.42 Kg, 1.0 wet%) at 25° C. under N₂. The resulting reactionmixture was then degassed with a steady hydrogen stream for three timesbefore being hydrogenated under 50-55 psig hydrogen pressure at ambienttemperature for 3-4 h. When the hydrogenation reaction was deemedcomplete, the reaction mixture was treated with methanol (1.0 L) andcharcoal (100 g). The resulting mixture was stirred at room temperaturefor 10 min before being filtered through a Celite® (200 g, pre-washedwith methanol) bed. The Celite®/charcoal bed was washed with methanol(2×500 mL). The filtrates were then concentrated in vacuo, and theresidual concentrated solution (4 L) was treated with toluene (4 L). Theresulting slurry was stirred at room temperature for 12 h. The solidswere collected by filtration, washed with toluene (2×1.0 L), and driedat 60° C. in vacuo to constant weight (20 h) to afford the crude desired1-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenyl-2-(trifluoroacetyl)-hydrazine(15, 1.365 Kg, 1.745 Kg theoretical, 77%) as white powder, which wasfound to be >95% pure and was used in the following reaction withoutfurther purification. The analytically pure material (15) was obtainedfrom recrystalization of the crude material obtained above fromEtOAc-heptanes. For 15: CIMS m/z 332 (M⁺−H, C₁₄H₁₈F₃N₃O₃).

Example 21

2,2,2-Trifluoro-N-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenylethane-hydrazonoylmesylate (16)

A solution1-[3-((N-tert-butoxy)carbonyl)aminomethyl]-phenyl-2-(trifluoroacetyl)hydrazine(15, 3.33 g, 0.01 mol) in EtOAc (20 mL) was treated with methanesulfonylchloride (1.38 g, 0.93 mL, 0.012 mol, 1.2 equiv), and the resultingsolution was added dropwise with a solution of N-methylmorpholine (NMM,1.11 g, 1.2 mL, 0.011 mol, 1.1 equiv) in EtOAc (20 mL) at 0-5° C. underN₂. The resulting reaction mixture was stirred at 0-5° C. for 30 minbefore being gradually warmed up to 25° C. for 12 h. When HPLC and TLCshowed that the reaction was deemed complete, the reaction mixture wastreated with H₂O (30 mL). The two layers were separated, and the aqueouslayer was extracted with EtOAc (20 mL). The combined organic extractswere washed with H₂O (2×20 mL) and saturated NaCl aqueous solution (20mL), dried over MgSO₄, and concentrated in vacuo. The residual oilycrude2,2,2-trifluoro-N-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenylethane-hydrazonoylmesylate (16, 3.86 g, 4.11 g theoretical, 94%) was found to be >97% pureby HPLC, which can be used in the following reaction without furtherpurification. The analytically pure product (16) was obtained by flashcolumn chromatography (SiO₂, 10-30% EtOAc-hexanes gradient elution)purification of the crude product obtained above. For 16: CIMS m/z 410(M⁺⁻H, C₁₅H₂₀F₃N₃O₅S).

Example 22

2,2,2-Trifluoro-N-[3-((N-tert-butoxy) carbonyl)aninomethyl]phenylethane-hydrazonoyl tosylate (17). Method A

A solution1-[3-((N-tert-butoxy)carbonyl)-aminomethyl]phenyl-2-(trifluoroacetyl)hydrazine(15, 3.33 g, 0.01 mol) in EtOAc (20 mL) was treated withp-toluenesulfonyl chloride (2.11 g, 0.011 mol, 1.1 equiv) at 0-5° C.under N₂, and the resulting solution was added dropwise with a solutionof N-methylmorpholine (NMM, 1.11 g, 1.2 mL, 0.011 mol, 1.1 equiv) inEtOAc (10 mL) at 0-5° C. under N₂. The resulting reaction mixture wasstirred at 0-5° C. for 30 min before being gradually warmed up to 25° C.for 4 h. When HPLC and TLC showed that the reaction was deemed complete,the reaction mixture was treated with H₂O (50 mL) and EtOAc (50 mL)).The two layers were separated, and the aqueous layer was extracted withEtOAc (30 mL). The combined organic extracts were washed with H₂O (2×20mL) and saturated NaCl aqueous solution (20 mL), dried over MgSO₄, andconcentrated in vacuo. The residual EtOAc slurry (15 mL) was thentitrated with hexanes (50 mL), and the resulting mixture was stirred at25° C. for 30 min to precipitate the crude desired product (17). Thewhite solids were collected by filtration, washed with heptanes (2×30mL), and dried at 40-45° C. in vacuo for 12 h to afford the crudedesired2,2,2-trifluoro-N-[3-((N-tert-butoxy)carbonyl)-aminomethyl]phenylethanehydrazonoyltosylate (17, 2.63 g, 4.87 g theoretical, 54%), which was found to bepure enough (>95%) by HPLC to do the following reaction without furtherpurification. The analytically pure product (17) was obtained fromrecrystalization of the crude product obtained above fromEtOAc/heptanes. For 17: CIMS m/z 486 (M⁺−H, C₂₁H₂₄F₃N₃O₅S). Thefiltrates were then evaporated in vacuo, and the residue was purified byflash column chromatography (SiO₂, 10-30% EtOAc-hexanes gradientelution) to afford the corresponding undesired sulfamide (18, 1.32 g,4.87 g theoretical, 27.1%) as yellow oil, which solidified upon standingat room temperature in vacuo. For 18: CIMS m/z 486 (M⁺−H,C₂₁H₂₄F₃N₃O₅S).

Example 23

2,2,2-Trifluoro-N-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenylethane-hydrazonoyltosylate (17). Method B

A solution1-[3-((N-tert-butoxy)carbonyl)-aminomethyl]phenyl-2-(trifluoroacetyl)hydrazine(15, 1.332 g, 4.0 mmol) in EtOAc (8 mL) was treated withp-toluenesulfonyl anhydride (1.37 g, 4.2 mmol, 1.05 equiv) at 0-5° C.under N₂, and the resulting solution was treated with pyridine (379 mg,0.39 mL, 4.8 mmol, 1.2 equiv) at 0-5° C. under N₂. The resultingreaction mixture was stirred at 0-5° C. for 10 min before beinggradually warmed up to 25° C. for 20 min. When HPLC and TLC showed thatthe reaction was deemed complete, the reaction mixture was treated withH₂O (10 mL) and EtOAc (20 mL). The two layers were separated, and theaqueous layer was extracted with EtOAc (10 mL). The combined organicextracts were washed with H₂O (2×10 mL) and saturated NaCl aqueoussolution (10 mL), dried over MgSO₄, and concentrated in vacuo. Theresidue was then purified by flash column chromatography (SiO2, 10-30%EtOAc-hexanes gradient elution) to afford the desired2,2,2-trifluoro-N-[3-((N-tert-butoxy)carbonyl)-aminomethyl]phenylethanehydrazonoyltosylate (17, 1.47 g, 1.95 g theoretical, 75.3%), which was found to beidentical as the material obtained from method A detailed above in everycomparable aspect, and the corresponding undesired sulfamide (18, 0.308g, 1.95 g theoretical, 15.8%) as yellow oil, which was also found to beidentical as the material obtained from method A detailed above in everycomparable aspect.

Example 24

2,2,2-Trifluoro-N-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenylethane-hydrazonoylbenzenesulfonate (19)

A solution of1-[3-((N-tert-butoxy)carbonyl)-aminomethyl]phenyl-2-(trifluoroacetyl)hydrazine(15, 1.665 g, 5.0 mmol) in ethyl acetate (10 mL) was treated withphenylsulfonyl chloride (971 mg, 702 mL, 5.5 mmol, 1.1 equiv) at roomtemperature under N₂, and the resulting reaction mixture was cooled to0-5° C. before being treated with N-methylmorpholine (NMM, 606 mg, 659mL, 1.2 equiv) at 0-5° C. under N₂. The reaction mixture was stirred at0-5° C. for 1 h before being gradually warmed to room temperature for 6h. When HPLC and TLC showed that the reaction was deemed complete, thereaction mixture was treated with H₂O (20 mL) and EtOAc (20 mL). The twolayers were separated, and the aqueous layer was extracted with EtOAc(20 mL). The combined organic extracts were washed with H₂O (2×20 mL)and saturated NaCl aqueous solution (20 mL), dried over MgSO₄, andconcentrated in vacuo. The residue was purified by flash columnchromatography (SiO₂, 10-30% EtOAc-hexanes gradient elution) to afford2,2,2-trifluoro-N-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenylethanehydrazonoylbenzenesulfonate (19, 1.36 g, 2.365 g theoretical, 57.5%) as whitesolids and1-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenyl-1-phenylsulfonyl-2-(trifluoroacetyl)hydrazine(20, 733 mg, 2.365 g theoretical, 31% ) as pale-yellow oil, whichsolidified upon standing in vacuo at room temperature. For 19: CIMS m/z472 (M⁺−H, C₂₀H₂₂F₃N₃O₅S); For 20: CIMS m/z 472 (M⁺−H, C₂₀H₂₂F₃N₃O₅S).

Example 25

2,2,2-Trifluoro-N-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenylethane-hydrazonoylchloride (21)

A solution of1-[3-((N-tert-butoxy)carbonyl)aminomethyl]-phenyl-2-(trifluoroacetyl)hydrazine(15, 3.33 g, 10.0 mmol) in ethyl acetate (20 mL) was treated withphenylsulfonyl chloride (1.94 g, 1.40 mL, 11.0 mmol, 1.1 equiv) at roomtemperature under N₂, and the resulting reaction mixture was cooled to0-5° C. before being treated dropwise with N,N-diisopropylethylamine(Hunig's base, 1.55 g, 2.09 mL, 12.0 mmol, 1.2 equiv) at 0-5° C. underN₂. The reaction mixture was stirred at 0-5° C. for 1 h. When HPLC andTLC showed that the reaction was deemed complete, the reaction mixturewas treated with H₂O (30 mL) and EtOAc (20 mL). The two layers wereseparated, and the aqueous layer was extracted with EtOAc (20 mL). Thecombined organic extracts were washed with H₂O (2×20 mL) and saturatedNaCl aqueous solution (20 mL), dried over MgSO₄, and concentrated invacuo. The residue was purified by flash column chromatography (SiO₂,10-20% EtOAc-hexanes gradient elution) to afford2,2,2-trifluoro-N-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenylethanehydrazonoylchloride (21, 3.24 g, 3.51 g theoretical, 92.3%) as white solids. For21: CIMS m/z 350/352 (M⁺−H, C₁₄H₁₇F₃NO₃O₂).

Example 26

Ethyl1-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenyl-3-trifluoromethyl-pyrazoline-5-carboxylate(22)

A solution of2,2,2-trifluoro-N-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenylethanehydrazonoylbenzenesulfonate (19, 170 mg, 0.36 mmol) in ethyl acetate (3 mL) wastreated with ethyl acrylate (72 mg, 78 μL, 0.72 mmol, 2.0 equiv) at roomtemperature under N₂, and the resulting reaction mixture was cooled downto 0-5° C. before being treated with triethylamine (TEA, 109 mg, 156 μL,1.08 mmol, 3.0 equiv) at 0-5° C. under N₂. The reaction mixture wasstirred at 0-5° C. for 30 min before being gradually warmed up to roomtemperature for 12 h. When HPLC and TLC showed that the reaction wasdeemed complete, the solvent were removed in vacuo, and the residue wasdirectly purified by flash column chromatography (SiO₂, 10-20%EtOAc-hexanes gradient elution) to afford ethyl1-[3-((N-tert-butoxy)carbonyl)amino-methyl]phenyl-3-trifluoromethylpyrazoline-5-carboxylate(22, 336 mg, 415 mg theoretical, 81%) as pale-yellow oil, whichsolidified upon standing in vacuo at room temperature. For 22: CIMS m/z414 (M⁺−H, C₁₉H₂₄F₃N₃O₄).

Example 27

Ethyl 1-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenyl-3-trifluoromethylpyrazole-5-carboxylate (23)

A solution of ethyl1-[3-((N-tert-butoxy)carbonyl)amino-methyl]phenyl-3-trifluoromethylpyrazoline-5-carboxylate(22, 115 mg, 0.28 mmol) in DMF (1.0 mL) was added dropwise to a solutionof potassium tert-butoxide (94 mg, 0.84 mmol, 3.0 equiv) at 0-5° C. Asteady stream of air was then bubbled into the reaction mixture for 30min at 0-5° C. When HPLC and TLC showed the reaction was deemedcomplete, the reaction mixture was treated with H₂O (5 mL) and EtOAc (10mL). The two layers were separated, and the aqueous layer was extractedwith EtOAc (5 mL). The combined organic extracts were washed with H₂O(2×5 mL) and saturated NaCl aqueous solution (5 mL), dried over MgSO₄,and concentrated in vacuo. The residue was purified by flash columnchromatography (SiO₂, 10-20 % EtOAc-hexanes gradient elution) to affordthe desired ethyl1-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenyl-3-trifluoro-methylpyrazole-5-carboxylate(23, 83 mg, 115 mg theoretical, 72%) as pale-yellow oil, whichsolidified at room temperature in vacuo. For 23: CIMS m/z 412 (M⁺−H,C₁₉H₂₂F₃N₃O₄).

Example 28

1-[3-((N-tert-Butoxy)carbonyl)aminomethyl]phenyl-5-[2-fluoro-4-(2-methyl-sulfonyl)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazoline(24)

A suspension of1-[3-(N-tert-butoxy)carbonyl)aminomethyl]phenyl-2-(trifluoroacetyl)hydrazine(15, 33.3 g, 0.1 mol) in EtOAc (200 mL) was treated with benzenesulfonylchloride (18.55 g, 13.4 mL, 0.105 mol, 1.05 equiv) at 0-5° C. under N₂,and the resulting mixture was treated dropwise withN,N-diisopropylethylamine (Hunig's base, 14.22 g, 19.2 mL, 0.11 mol, 1.1equiv) at 0-5° C. under N₂. The resulting reaction mixture was stirredat 0-5° C. for 45 min. When HPLC and TLC showed that the transformationof starting material (15) into the corresponding2,2,2-trifluoro-N-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenylethane-hydrazonoylchloride (21) was deemed complete, the reaction mixture was treated withN-[2-fluoro-4-(2-methylsulfonyl)phenyl]phenyl acrylamide (12, 30.94 g,0.092 mol, 0.97 equiv) and triethylamine (TEA, 30.3 g, 43.3 mL, 0.3 mol,3.0 equiv) at 25° C. under N₂. The resulting reaction mixture wassubsequently warmed up to gentle reflux (80° C.) for 24 h. When HPLCshowed that the cycloaddition reaction was deemed complete, the reactionmixture was cooled down to room temperature before being treated withH₂O (200 mL) and EtOAc (200 mL). The mixture was stirred at roomtemperature for 30 min. The two layers were separated. The aqueous layerwas extracted with EtOAc (100 mL). The combined organic extracts werewashed with H₂O (2×200 mL) and saturated NaCl aqueous solution (200 mL),dried over MgSO₄, and concentrated in vacuo to leave a slurry of thecrude cycloaddition product (24) in about 100 mL of EtOAc. The residualslurry was then treated with heptanes (500 mL), and the resultingmixture was stirred at room temperature for 1 h before being cooled downto 0° C. for an additional 2 h. The solids were collected by filtration,washed with heptanes (2×100 mL), and dried in vacuo at 40-45° C. for 12h to afford the crude desired cycloaddition product (24, 51.2 g, 61.5 gtheoretical, 83.3%). The crude cycloaddition product 24 (>98% HPLC areapure) was then directly recrystalized from EtOAc/heptane (50%) to affordthe pure 24 (40.45 g, 61.5 g theoretical, 65.8%) as white powder, whichwas found to be 100% area pure by HPLC and was used in the followingreaction without further purification. For 24: CIMS m/z 633 (M⁺−H,C₃₀H₃₀F₄N₄O₅S).

Example 29

1-[3-(N-tert-Butoxy)carbonyl)aminomethyl]phenyl-5-[2-fluoro-4-(2-methyl-sulfonyl)phenyl]phenylcarbamoyl-3-trifluoramethylpyrazole(25)

A solution of1-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenyl-5-[2-fluoro-4-(2-methylsulfonyl)phenyl]-phenylcarbamoyl-3-trifluoromethylpyrazoline(24, 5.0 g, 7.9 mmol) in DMF (25 mL) was added dropwise to a solution ofpotassium tert-butoxide (2.7 g, 24.5 mmol, 3.1 equiv) in DMF (15 ml) at−20° C. A steady stream of 7% of O₂ in N₂ was then bubbled into thereaction mixture for 6 h at −20-25° C. When HPLC and TLC showed thereaction was deemed complete, the reaction mixture was treated with 1.0N aqueous citric acid solution (250 mL) at 0-5° C. The resulting mixturewas then stirred at room temperature for 12 h to precipitate the crudedesired oxidation product. The solids were collected by filtration,washed with heptanes (2×40 mL), and dried at 40-45° C. in vacuo for 12 hto afford the crude1-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenyl-5-[2-fluoro-4-(2-methylsulfonyl)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazole(25, 4.3 g, 5.0 g theoretical, 86%) as off-white crystals, which wasfound to be >95% pure by HPLC. The filtrates were then extracted withEtOAc (2×50 mL). The combined organic extracts were washed with H₂O(2×20 mL) and saturated NaCl aqueous solution (20 mL), dried over MgSO₄,and concentrated in vacuo to afford an additional amount of the crude 25(200 mg, 5.0 g theoretical, 4%; total 90% yield) as yellow solids. Thecrude 25 was directly used in the following reaction without furtherpurification and the analytically pure 25 was obtained from therecrystalization of the crude product obtained above fromEtOAc-heptanes. For 25: CIMS m/z 631 (M⁺−H, C₃₀H₂₈F₄N₄O₅S).

Example 30

1-(3-Aminomethyl)phenyl-5-[2-fluoro-4-(2-methylsulfonyl)phenyl]phenyl-carbonyl-3-trifluoromethylpyrazolehydrogen chloride salt (26, SW423)

A suspension of1-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenyl-5-[2-fluoro-4-(2-methylsulfonyl)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazole(25, 13.7 g, 21.7 mmol) in 5-6 N HCl in isopropyl alcohol (IPA, 120 mL)was stirred at room temperature for 2 h. When HPLC and TLC showed thatthe reaction was deemed complete, the solvent was removed in vacuo. Theresidue was dissolved in MeOH (50 mL) and ethyl acetate (50 mL) atgentle reflux (60-65° C.), and the resulting hot solution was thentreated with charcoal (activated carbon, 1.5 g), and the resultingmixture was refluxed for an additional 1 h. Filtration of the mixturethrough a Celite® bed, and the Celite® bed was washed with MeOH/EtOAc(1:1 v/v, 20 mL). The filtrates were then stirred at room temperaturefor 1 h before being cooled down to 0-5° C. for an additional 1 h. Thewhite solids were collected by filtration, washed with EtOAc (30 mL),and dried in vacuo at 40-45° C. for 12 h to afford the desired1-(3-aminomethyl)phenyl-5-[2-fluoro-4-(2-methylsulfonyl)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazolehydrogen chloride salt (26, 9.87 g, 12.35 g theoretical, 80%) as whitecrystals, which was found to be >99.5% pure by HPLC and to be identicalas the material obtained from another totally different syntheticapproach in every comparable aspect.

Example 31

1-[3-((N-tert-Butoxy)carbonyl)aminomethyl]phenyl-5-(2-fluoro-4-brono)phenyl-carbamoyl-3-trifluoromethylpyrazoline(27)

A suspension of1-[3-(N-tert-butoxy)carbonyl)aminomethyl]phenyl-2-(trifluoroacetyl)hydrazine(15, 33.3 g, 0.1 mol) in EtOAc (200 mL) was treated with benzenesulfonylchloride (18.55 g, 13.4 mL, 0.105 mol, 1.05 equiv), and the resultingmixture was treated dropwise with N,N-diisopropylethylamine (Hunig'sbase, 14.22 g, 19.2 mL, 0.11 mol, 1.1 equiv) at 0° C. under N₂. Theresulting reaction mixture was stirred at 0-5° C. for 45 min. When HPLCand TLC showed that the transformation of starting material (15) intothe corresponding2,2,2-trifluoro-N-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenylethanehydrazonoylchloride (21) was deemed complete, the reaction mixture was treated withN-(2-fluoro-4-bromo)phenyl acrylamide (9, 23.18 g, 0.095 mol, 0.95equiv) and triethylamine (30.3 g, 43.3 mL, 0.3 mol, 3.0 equiv) at 25° C.under N₂. The resulting reaction mixture was subsequently warmed up togentle reflux (80° C.) for 20 h. When HPLC showed that the cycloadditionreaction was deemed complete, the reaction mixture was cooled down toroom temperature before being treated with H₂O (200 mL) and EtOAc (100mL). The mixture was stirred at room temperature for 30 min. The twolayers were separated. The aqueous layer was extracted with EtOAc (100mL). The combined organic extracts were washed with H₂O (2×200 mL) andsaturated NaCl aqueous solution (200 mL), dried over MgSO₄, andconcentrated in vacuo to leave a slurry of the crude cycloadditionproduct (27) in about 70 mL of EtOAc. The residual slurry was thentreated with heptanes (300 mL), and the resulting mixture was stirred atroom temperature for 1 h before being cooled down to 0° C. for anadditional 1 h. The solids were collected by filtration, washed withheptanes (2×50 mL), and dried in vacuo at 40-45° C. for 12 h to affordthe crude desired cycloaddition product (27, 44.9 g, 53.1 g theoretical,84.6%). The crude cycloaddition product 27 was found to be pure enough(>99% HPLC area pure) to do the following reaction without furtherpurification. The analytical pure material was obtained from therecrystalization of the crude 27 from EtOAc/heptanes. For 27: CIMS m/z558/560 (M⁺−H, C₂₃H₂₃F₄BrN₄O₃).

Example 32

1-[3-((N-tert-Butoxy)carbonyl)aminomethyl]phenyl-5-[2-fluoro-4-(2-methylthio)-phenyl]phenylcarbamoyl-3-trifluoromethylpyrazoline(29)

A suspension of1-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenyl-5-(2-fluoro-4-bromo)-phenylcarbamoyl-3-trifluoromethylpyrazoline(27, 2.795 g, 5.0 mmol) in toluene (20 mL) was treated with2-methylthiophenylboronic acid (28, 1.002 g, 6.0 mmol, 1.2 equiv),sodium carbonate (Na₂CO₃, 1.33 g. 12.5 mmol, 2.5 equiv), ethanol (EtOH,5 mL), and water (5 mL) at room temperature. The resulting mixture wasdegassed three times under N₂ before being treated with Pd(PPh₃)₄ (116mg, 0.1 mmol, 2% equiv). The resulting reaction mixture was subsequentlydegassed three times again under N₂ before being warmed up to gentlereflux (76-77° C.) for 4 h. When HPLC and TLC showed that the reactionwas deemed complete, the reaction mixture was cooled down to roomtemperature and treated with EtOAc (40 mL) and water (40 mL). Themixture was stirred at room temperature for 10 min, and the two layerswere separated. The aqueous layer was extracted with EtOAc (20 mL). Thecombined organic extracts were washed with H₂O (2×20 mL) and saturatedNaCl aqueous solution (20 mL), dried over MgSO₄, and concentrated invacuo. The residual solution of the crude coupling product (29) inEtOAc/toluene (20 mL) was titrated with heptanes (80 mL), and theresulting mixture was stirred at room temperature for 1 h before beingcooled down to 0-5° C. for an additional 1 h. The solids were collectedby filtration and washed with heptanes (2×30 mL), dried in vacuo at40-45° C. for 12 h to afford the crude desired1-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenyl-5-[2-fluoro-4-(2-methylthio)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazoline(29, 2.78 g, 3.01 g theoretical, 92.4%), which was found to be >99% pureby HPLC and can be used in the following reaction without furtherpurification. The analytical pure product (29) was obtained fromrecrystalization of the crude 29 from EtOAc/heptanes. For 29: CIMS m/z601 (M⁺−H, C₃₀H₃₀F₄N₄O₃S).

Example 33

1-[3-((N-tert-Butoxy)carbonyl)aminomethyl]phenyl-5-[2-fluoro-4-(2-(N-tert-butylamino)sulfonyl)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazoline(31)

A suspension of1-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenyl-5-(2-fluoro-4-bromo)-phenylcarbamoyl-3-trifluoromethylpyrazoline(27, 1.118 g, 2.0 mmol) in toluene (8 mL) was treated with2-[(N-tert-butylamino)sulfonyl]phenylboronic acid (30, 617 mg, 2.4 mmol,1.2 equiv), sodium carbonate (Na₂CO₃, 636 mg. 6.0 mmol, 3.0 equiv),ethanol (EtOH, 2 mL), and water (2 mL) at room temperature. Theresulting mixture was degassed three times under N₂ before being treatedwith Pd(PPh₃)₄ (46 mg, 0.04 mmol, 2% equiv). The resulting reactionmixture was subsequently degassed three times again under N₂ beforebeing warmed up to gentle reflux (76-77° C.) for 4 h. When HPLC and TLCshowed that the reaction was deemed complete, the reaction mixture wascooled down to room temperature and treated with EtOAc (20 mL) and water(20 mL). The mixture was stirred at room temperature for 10 min, and thetwo layers were separated. The aqueous layer was extracted with EtOAc(10 mL). The combined organic extracts were washed with H₂O (2×10 mL)and saturated NaCl aqueous solution (10 mL), dried over MgSO₄, andconcentrated in vacuo. The residue was purified by flash columnchromatography (SiO₂, 5-20% EtOAc-hexanes gradient elution) to affordthe pure desired1-[3-((N-tert-butoxy)carbonyl)amino-methyl]phenyl-5-[2-fluoro-4-(2-((N-tert-butyl-amino)sulfonyl)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazoline(31, 1.30 g, 1.382 g theoretical, 94.1%) as white solids. For 31: CIMSm/z 690 (M⁺−H, C₃₃H₃₇F₄N₅O₅S).

Example 34

1-(3-Cyano)phenyl-5-[2-fluoro-4-(2-methylthio)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazoline(32)

A suspension of1-(3-cyano)phenyl-5-(2-fluoro-4-bromo)phenylcarbamoyl-3-trifluoromethylpyrazoline(10, 9.10 g, 20.0 mmol) in toluene (60 mL) was treated with2-methylthiophenylboronic acid (28, 4.0 g, 24.0 mmol, 1.2 equiv), sodiumcarbonate (Na₂CO₃, 6.36 g. 60.0 mmol, 3.0 equiv), ethanol (EtOH, 30 mL),and water (30 mL) at room temperature. The resulting mixture wasdegassed three times under N₂ before being treated with Pd(PPh₃)₄ (462.4mg, 0.4 mmol, 2% equiv). The resulting reaction mixture was subsequentlydegassed three times again under N₂ before being warmed up to gentlereflux (76-77° C.) for 4 h. When HPLC and TLC showed that the reactionwas deemed complete, the reaction mixture was cooled down to roomtemperature and treated with water (100 mL). The mixture was stirred atroom temperature for 2 h. The solids precipitated from the mixture werecollected by filtration, washed with H₂O (2×50 mL) and 25%EtOAc-heptanes (2×50 mL), and dried in vacuo at 40-45° C. for 12 h toafford the crude desired1-(3-cyano)phenyl-5-(2-fluoro-4-(2-methylthio)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazoline(32, 9.21 g, 9.96 g theoretical, 92.5%), which was found to be >99% pureby HPLC and was used in the following reaction without furtherpurification. The analytically pure product (32) was obtained fromrecrystalization of the crude material obtained above fromEtOAc-heptanes. For 32: CIMS m/z 497 (M⁺−H, C₂₅H₁₈F₄N₄OS).

Example 35

1-(3-Cyano)phenyl-5-[2-fluoro-4-(2-(N-tert-butylamino)sulfonyl)phenyl]phenyl-carbamoyl-3-trifluoromethylpyrazoline(33)

A suspension of1-(3-cyano)phenyl-5-(2-fluoro-4-bromo)phenylcarbamoyl-3-trifluoromethylpyrazoline(10, 910 mg, 2.0 mmol) in toluene (8 mL) was treated with2-[(N-tert-butylamino)sulfonyl]phenylboronic acid (30, 617 mg, 2.4 mmol,1.2 equiv), sodium carbonate (Na₂CO₃, 636 mg, 6.0 mmol, 3.0 equiv),ethanol (EtOH, 2 mL), and water (2 mL) at room temperature. Theresulting mixture was degassed three times under N₂ before being treatedwith Pd(PPh₃)₄ (46 mg, 0.04 mmol, 2% equiv). The resulting reactionmixture was subsequently degassed three times again under N₂ beforebeing warmed up to gentle reflux (76-77° C.) for 4 h. When HPLC showedthat the reaction was deemed complete, the reaction mixture was cooleddown to room temperature and treated with EtOAc (20 mL) and water (20mL). The mixture was stirred at room temperature for 10 min. The twolayers were separated, and the aqueous layer was extracted with EtOAc(10 mL). The combined organic extracts were washed with H₂O (2×10 mL)and saturated NaCl aqueous solution (10 mL), dried over MgSO₄, andconcentrated in vacuo. The residue was then purified by flash columnchromatography (SiO₂, 5-20% EtOAc-heptanes gradient elution) to affordthe desired1-(3-cyano)phenyl-5-[2-fluoro-4-(2-(N-tert-butylamino)sulfonyl)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazoline(33, 1.1. g, 1.174 g theoretical, 93.6%) as white solids. For 33: CIMSm/z 586 (M⁺−H, C₂₈H₂₅F₄N₅O₃S).

Example 36

1-(3-Cyano)phenyl-5-[2-fluoro-4-(2-methylthio)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazol(34)

A suspension of1-(3-cyano)phenyl-5-(2-fluoro-4-bromo)-phenylcarbamoyl-3-trifluoromethylpyrazole(11, 4.53 g, 10.0 mmol) in toluene (30 mL) was treated with2-(methylthio)phenylboronic acid (28, 2.0 g, 12.0 mmol, 1.2 equiv),sodium carbonate (Na₂CO₃, 3.18 g. 30.0 mmol, 3.0 equiv), ethanol (EtOH,10 mL), and water (10 mL) at room temperature. The resulting mixture wasdegassed three times under N₂ before being treated with Pd(PPh₃)₄ (231.2mg, 0.2 mmol, 2% equiv). The resulting reaction mixture was subsequentlydegassed three times again under N₂ before being warmed up to gentlereflux (76-77° C.) for 12 h. When HPLC and TLC showed that the reactionwas deemed complete, the reaction mixture was cooled down to roomtemperature and treated with water (100 mL). The mixture was stirred atroom temperature for 1 h. The solids precipitated from the mixture werecollected by filtration and washed with H₂O (2×50 mL) and 25%EtOAc-heptanes (2×50 mL), dried in vacuo at 40-45° C. for 12 h to affordthe crude desired1-(3-cyano)phenyl-5-[2-fluoro-4-(2-methylthio)phenyl]phenyl-carbamoyl-3-trifluoromethylpyrazole(34, 3.3 g, 4.96 g theoretical, 66.5%), which was found to be >99% pureby HPLC and can be used in the following reaction without furtherpurification. The two layers of the filtrate were separated, and theaqueous layer was extracted with EtOAc (30 mL). The combined organicextracts were washed with H₂O (2×20 mL) and saturated NaCl aqueoussolution (20 mL), dried over MgSO₄, and concentrated in vacuo. Theresidual slurry (15 mL) was titrated with heptanes (100 mL), and theresulting mixture was stirred at room temperature for an additional 30min. The solids were collected by filtration and washed with 25%EtOAc-heptanes (2×20 mL), dried in vacuo at 40-45° C. for 12 h to affordthe second batch of the crude desired coupling product (34, 1.30 g. 4.96g theoretical, 26.2%), which was found to be >99% pure by HPLC and canbe used in the following reaction without further purification. Theanalytically pure product (34) was obtained from recrystallization ofthe crude material obtained above from EtOAc/heptanes. For 34: CIMS m/z495 (M⁺−H, C₂₅H₁₆F₄N₄OS).

Example 37

1-(3-Cyano)phenyl-5-[2-fluoro-4-(2-(N-tert-butylamino)sulfonyl)phenyl]phenyl-carbamoyl-3-trifluoromethylpyrazole(35)

A suspension of1-(3-cyano)phenyl-5-(2-fluoro-4-bromo)phenylcarbamoyl-3-trifluoromethylpyrazole(11, 906 mg, 2.0 mmol) in toluene (8 mL) was treated with2-[(tert-butylamino)sulfonyl]phenylboronic acid (30, 617 mg, 2.4 mmol,1.2 equiv), sodium carbonate (Na₂CO₃, 636 mg. 6.0 mmol, 3.0 equiv),ethanol (EtOH, 2 mL), and water (2 mL) at room temperature. Theresulting mixture was degassed three times under N₂ before being treatedwith Pd(PPh₃)₄ (46 mg, 0.04 mmol, 2% equiv). The resulting reactionmixture was subsequently degassed three times again under N₂ beforebeing warmed up to gentle reflux (76-77° C.) for 16 h. When HPLC and TLCshowed that the reaction was deemed complete, the reaction mixture wascooled down to room temperature and treated with water (20 mL) and EtOAc(20 mL). The mixture was stirred at room temperature for 10 min. The twolayers were separated, and the aqueous layer was extracted with EtOAc(10 mL). The combined organic extracts were washed with H₂O (2×10 mL)and saturated aqueous NaCl solution (10 mL), dried over MgSO₄, andconcentrated in vacuo. The residue was purified by flash columnchromatography (SiO₂, 5-25% EtOAc-hexanes gradient elution) to affordthe desired1-(3-cyano)phenyl-5-[2-fluoro-4-(2-(N-tert-butylamino)sulfonyl)phenyl]phenyl-carbamoyl-3-trifluoromethyl-pyrazole(35, 984 mg, 1.17 g theoretical, 84.1%) as colorless oil, which wassolidified at room temperature in vacuo. For 35: CIMS m/z 584 (M⁺−H,C₂₈H₂₃F₄N₅O₃S).

Example 38

1-(3-Cyano)phenyl-5-[2-fluoro-4-(2-(N-tert-butylamino)sulfonyl)phenyl]phenyl-carbamoyl-3-trifluoromethylpyrazole(35)

A solution of1-(3-cyano)phenyl-5-[2-fluoro-4-(2-(N-tert-butylamino)sulfonyl)phenyl)phenyl-carbamoyl-3-trifluoromethyl-pyrazoline(33, 585 mg, 1.0 mmol) in THF (4 mL) was treated withN-chlorosuccinimide (NCS, 140 mg, 1.05 mmol, 1.05 equiv) at 0-5° C., andthe resulting reaction mixture was stirred at 0-5° C. for 10 min beforebeing gradually warmed up to room temperature for 2 h. When TLC and HPLCshowed that the reaction was deemed complete, the reaction mixture wastreated with EtOAc (10 mL) and water (10 mL). The two layers wereseparated, and the aqueous layer was extracted with EtOAc (10 mL). Thecombined organic extracts were washed with H₂O (2×10 mL) and saturatedNaCl aqueous solution (10 mL), dried over MgSO₄, and concentrated invacuo. The residual pale-yellow oil was solidified at room temperaturein vacuo to afford the crude desired1-(3-cyano)phenyl-5-[2-fluoro-4-(2-(N-tert-butyl-amino)sulfonyl)phenyl]phenylcarbamoyl-3-trifluoromethyl-pyrazole(35, 550 mg, 583 mg theoretical, 94%), which was found to be >99% pureby HPLC and to be identical as the material obtained from the differentsynthetic approach detailed above in every comparable aspect.

Example 39

1-[3-((N-tert-Butoxy)carbonyl)aminomethyl]phenyl-5-(2-fluoro-4-bromo)phenyl-carbamoyl-3-trifluoromethylpyrazole(36)

A solution of1-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenyl-5-(2-fluoro-4-bromo)phenylcarbamoyl-3-trifluoro-methyl-pyrazoline(27, 1.0 g, 1.8 mmol) in DMF (5 mL) was added dropwise to a solution ofpotassium tert-butoxide (645 mg, 5.75 mmol, 3.2 equiv) in DMF (5 mL) at−10° C. A steady stream of 7% of O₂ in N₂ was then bubbled into thereaction mixture at −10-5° C. for 4 h. When HPLC and TLC showed thereaction was deemed complete, the reaction mixture was treated with 1.0N aqueous citric acid solution (20 mL) at 0-5° C. The resulting solutionwas then extracted with EtOAc (3×20 mL). The combined organic extractswere washed with H₂O (2×10 mL) and saturated NaCl aqueous solution (10mL), dried over MgSO₄, and concentrated in vacuo. The residue was thenpurified by flash column chromatography (SiO₂, 10-20 EtOAc-hexanesgradient elution) to afford the desired1-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenyl-5-(2-fluoro-4-bromo)phenyl-carbamoyl-3-trifluoromethylpyrazole(36, 560 mg, 1.0 g theoretical, 56%) as white solids. For 36: CIMS m/z556/558 (M⁺−H, C₂₃H₂₁F₄BrN₄O₃)

Example 40

1-[3-((N-tert-Butoxy)carbonyl)aminomethyl]phenyl-5-[2-fluoro-4-(2-methylthio)-phenyl]phenylcarbamoyl-3-trifluoromethylpyrazole(37)

A solution of1-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenyl-5-[2-fluoro-4-(2-methylthio)phenyl]phenyl-carbamoyl-3-trifluoromethylpyrazoline(29, 637 mg, 1.1 mmol) in DMF (5 mL) was added dropwise to a solution ofpotassium tert-butoxide (416 mg, 3.72 mmol, 3.5 equiv) in DMF (5 ml) at0-5° C. A steady stream of 7% of O₂ in N₂ was then bubbled into thereaction mixture at 0-10° C. for 2.5 h. When HPLC and TLC showed thereaction was deemed complete, the reaction mixture was treated with 1.0N aqueous citric acid solution (20 mL) at 0-10° C. The resultingsolution was then extracted with tert-butyl methyl ether (TBME, 3×20mL). The combined organic extracts were washed with H₂O (2×10 mL) andsaturated NaCl aqueous solution (10 mL), dried over MgSO₄, andconcentrated in vacuo. The residue was then purified by flash columnchromatography (SiO₂, 10-20% EtOAc-hexanes gradient elution) to affordthe crude1-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenyl-5-[2-fluoro-4-(2-methylthio)phenyl]phenyl-carbamoyl-3-trifluoromethylpyrazole(37, 420 mg, 637 mg theoretical, 66%) as white solids. For 37: CIMS m/z599 (M⁺−H, C₃₀H₂₈F₄N₄O₃S).

Example 41

1-[3-((N-tert-Butoxy)carbonyl)aminomethyl]phenyl-5-[2-fluoro-4-(2-(N-tert-butyl-amino)sulfonyl)phenyl]phenylcarbanoyl-3-trifluoromethylpyrazole(38)

A solution of1-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenyl-5-[2-fluoro-4-(2-(N-tert-butyl-amino)sulfonyl)phenyl]phenylcarbamoyl-3-trifluoromethyl-pyrazoline(31, 587 mg, 0.85 mmol) in DMF (2 mL) was added dropwise to a solutionof potassium tert-butoxide (305 mg, 2.72 mmol, 3.2 equiv) in DMF (2 ml)at 0-5° C. A steady stream of 7% of O₂ in N₂ was then bubbled into thereaction mixture at 0-5° C. for 6 h. When HPLC and TLC showed thereaction was deemed complete, the reaction mixture was treated with 1.0N aqueous citric acid solution (20 mL) at 0-5° C. The resulting solutionwas then extracted with EtOAc (3×15 mL). The combined organic extractswere washed with H₂O (2×10 mL) and saturated NaCl aqueous solution (10mL), dried over MgSO₄, and concentrated in vacuo. The residue was thenpurified by flash column chromatography (SiO₂, 10-20% EtOAc-hexanesgradient elution) to afford 1-[3-((N-tert-butoxy)carbonyl)aminomethyl]-phenyl-5-[2-fluoro-4-(2-(N-tert-butylamino)sulfonyl)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazoline(38, 352 mg, 587 mg theoretical, 60%) as white solids. For 38: CIMS m/z688 (M⁺−H, C₃₃H₃₅F₄N₅O₅S).

Example 42

1-(aminomethyl)phenyl-5-[2-fluoro-4-(2-aminosulfonyl)phenyl]phenylcarbaoyl-3-trifluoromethylpyrazolehydrogen chloride salt (39)

A solution of1-[3-((N-tert-Butoxy)carbonyl)-aminomethyl]-phenyl-5-[2-fluoro-4-(2-(N-tert-butylamino)-sulfonyl)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazoline(38, 128 mg, 0.2 mmol) in 5-6 N HCl in isopropyl alcohol (4 mL) waswarmed up to reflux for 48 h. The solvent was removed in vacuo, and theresidue was then directly recrystallized from MeOH and EtOAc to affordthe desired1-(aminomethyl)phenyl-5-[2-fluoro-4-(2-aminosulfonyl)-phenyl]phenyl-carbamoyl-3-trifluoromethylpyrazolehydrogen chloride salt (39, 57 mg, 106 mg theoretical, 55% ) as whitecrystals, which was found to be identical as the material obtained fromtotally different synthetic approach in every comparable aspect.

Example 43

1-(3-Cyano)phenyl-5-[2-fluoro-4-(2-methylsulfonyl)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazoline(13)

A suspension of1-(3-cyano)phenyl-5-[2-fluoro-4-(2-methylthio)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazoline(32, 2.49 g, 5.0 mmol) in ethyl acetate (EtOAc, 45 mL) was treateddropwise with a solution of mCPBA (57-86% pure, 3.78 g, 12.5 mmol, 2.5equiv) in EtOAc (15 mL) at 0-5° C., and the resulting reaction mixturewas stirred at 0-5° C. for 30 min before being warmed up to roomtemperature for 4 h. When HPLC showed the reaction was deemed complete,the reaction mixture was cooled down to 0-5° C. and treated with asaturated aqueous Na₂SO₃ solution (20 mL) and a saturated aqueous Na₂CO₃solution (20 mL). The resulting mixture was then gradually warmed up toroom temperature and stirred at room temperature for 30 min. The twolayers were separated, and the aqueous layer was extracted with EtOAc(20 mL). The combined organic extracts were washed with H₂O (2×20 mL)and saturated NaCl aqueous solution (20 mL), dried over MgSO₄, andconcentrated in vacuo. The residue was purified by flash columnchromatography (SiO₂, 10-30% EtOAc-hexanes gradient elution) to affordthe desired1-(3-cyano)phenyl-5-[2-fluoro-4-(2-methyl-sulfonyl)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazoline(13, 2.15 g, 2.65 g theoretical, 81%) as white solids, which was foundto be identical as the material obtained from the different syntheticapproach detailed above in every comparable aspect.

Example 44

1-(3-Cyano)phenyl-5-[2-fluoro-4-(2-methylsulfonyl)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazole(14)

A suspension of1-(3-cyano)phenyl-5-[2-fluoro-4-(2-methylthio)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazole(34, 2.48 g, 5.0 mmol) in ethyl acetate (EtOAc, 45 mL) was treateddropwise with a solution of mCPBA (57-86% pure, 3.78 g, 12.5 mmol, 2.5equiv) in EtOAc (15 mL) at 0-5° C., and the resulting reaction mixturewas stirred at 0-5° C. for 30 min before being warmed up to roomtemperature for 4 h. When HPLC showed the reaction was deemed complete,the reaction mixture was cooled down to 0-5° C. and treated with asaturated aqueous Na₂SO₃ solution (20 mL) and a saturated aqueous Na₂CO₃solution (20 mL). The resulting mixture was then gradually warmed up toroom temperature and stirred at room temperature for 30 min. The twolayers were separated, and the aqueous layer was extracted with EtOAc(20 mL). The combined organic extracts were washed with H₂O (2×20 mL)and saturated aqueous NaCl solution (20 mL), dried over MgSO₄, andconcentrated in vacuo. The residual slurry of the crude product in ethylacetate (20 mL) was titrated with heptanes (50 mL) at room temperaturefor 30 min before the mixture was cooled down to 0-5° C. for 1 h. Thesolids were collected by filtration, washed with heptanes (2×20 mL), anddried at 40-45° C. in vacuo for 12 h to afford the crude desired1-(3-cyano)phenyl-5-[2-fluoro-4-(2-methylsulfonyl)phenyl]phenylcarbamoyl-3-trifluoromethylpyrazole(14, 2.10 g, 2.64 g theoretical, 80%) as white solids, which was foundto be identical as the material obtained from the different syntheticapproach detailed above in every comparable aspect.

Example 45

1-[3-((N-tert-Butoxy)carbonyl)aminomethyl]phenyl-5-[2-fluoro-4-(2-methyl-sulfonyl)phenyl]pheylcarbamoyl-3-trifluorcmthylpyrazoline(24) and1-[3-((N-tert-Butoxy)carbonyl)aminomethyl]phenyl-5-[2-fluoro-4-(2-methyloulfonyl)phenyl]-phenylcarbamoy-3-trifluoroethylpyrazole(25)

A suspension of1-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenyl-5-[2-fluoro-4-(2-methylthio)phenyl]phenyl-carbamoyl-3-trifluoromethylpyrazoline(29, 1.204 g, 2.0 mmol) in ethyl acetate (EtOAc, 15 mL) was treateddropwise with a solution of mCPBA (57-86% pure, 1.513 g, 5.0 mmol, 2.5equiv) in EtOAc (5 mL) at 0-5° C., and the resulting reaction mixturewas stirred at 0-5° C. for 30 min before being warmed to roomtemperature for 2 h. When HPLC and TLC showed the starting material 29was totally consumed, the reaction was found to produce a mixture of thefour compounds. The reaction mixture was subsequently cooled down to0-5° C. and treated with one additional equivalent of mCPBA (605 mg),and the resulting reaction mixture was stirred at room temperature foran additional 2 h. The HPLC showed that the reaction produced a mixtureof 24 and 25 in a ratio of 4 to 5. Therefore, the reaction mixture wastreated with a saturated aqueous Na₂SO₃ solution (10 mL) and a saturatedaqueous Na₂CO₃ solution (20 mL) at 0-5° C. The resulting mixture wasthen gradually warmed up to room temperature and stirred at roomtemperature for 30 min. The two layers were separated, and the aqueouslayer was extracted with EtOAc (20 mL). The combined organic extractswere washed with H₂O (2×20 mL) and saturated NaCl aqueous solution (20mL), dried over MgSO₄, and concentrated in vacuo. The residue waspurified by flash column chromatography (SiO₂, 5-25% EtOAc-hexanesgradient elution) to afford1-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenyl-5-[2-fluoro-4-(2-methyl-sulfonyl)phenyl]phenylcarbamoyl-3-trifluoro-methylpyrazoline(24, 362 mg, 1.268 g theoretical, 28.6%) as white solids and1-[3-((N-tert-butoxy)carbonyl)aminomethyl]phenyl-5-(2-fluoro-4-(2-methylsulfonyl)phenyl]-phenylcarbamoyl-3-trifluoromethylpyrazole(25, 440 mg, 1.264 g theoretical, 34.8%) as white solids. Both compounds24 and 25 were found to be identical as the materials obtained from thedifferent synthetic approach detailed above in every comparable aspect.

Example 46

1-(4-Fluoro-3-cyano)phenyl-2-(trifluroacetyl)hydrazine (40)

A suspension of 4-fluoro-3-cyanophenylhydrazine hydrogen chloride salt(37.5 g, 0.2 mol) in THF (200 mL) was treated with solid NaHCO₃ (33.6 g,0.4 mol, 2.0 equiv) at 0° C. under N₂, and the resulting reactionmixture was stirred at 0-5° C. for 30 min before being treated dropwisewith trifluoroacetic acid anhydride (TFAA, 50.40 g, 33.9 mL, 0.24 mol,1.2 eqiuv) at 0° C. under N₂. The reaction mixture was then warmed to25° C. for 12 h before being filtrated. The solvent of the filtrateswere removed in vacuo, and the residue was added EtOAc (50 mL) andheptanes (30 mL), and the resulting mixture was stirred at roomtemperature for 15 min. The off-white solids were collected byfiltration, washed with 30% EtOAc-heptanes, and dried at 40-45° C. invacuo for 12 h to afford the crude desired1-(4-fluoro-3-cyano)phenyl-2-(trifluroacetyl)hydrazine (40, 16.9 g, 49.4g theoretical, 34.2%), which was found to be pure enough to do thefollowing reaction without further purification. The filtrates were thenevaporated in vacuo, and the residue was purified by flash columnchromatography (SiO₂, 10-40% EtOAc-heptanes gradient elution) to affordan additional batch of1-(4-fluoro-3-cyano)phenyl-2-(trifluroacetyl)hydrazine (40, 13.6 g, 49.4g theoretical, 27.5%; total 61.7% yield) as pale-yellow solids. Theanalytically pure product (40) was obtained by recrystalization of crudeproduct obtained above from EtOAc-heptanes. For 40: CIMS m/z 246 (M⁺−H,C₉H₅F₄N₃O).

Example 47

2,2,2-Trifluoro-N-(4-fluoro-3-cyano)phenylethanehydrazonyl tosylate (41)

A solution of 1-(4-fluoro-3-cyano)phenyl-2-(trifluoroacetyl)hydrazine(40, 12.35 g, 50 mmol) in ethyl acetate (100 mL) was treated withp-toluenesulfonyl anhydride (97% pure, 17.67 g, 52.5 mmol, 1.05 equiv)at 0° C. under N₂, and the resulting mixture was treated dropwise withpyridine (5.93 g, 6.1 mL, 75 mmol, 1.5 equiv) at 0° C. under N₂. Thereaction mixture was then gradually warmed up to room temperature for 6h. When HPLC and TLC showed the reaction was deemed complete, thereaction mixture was treated with water (100 mL) and EtOAc (100 mL). Thetwo layers were separated, and the aqueous layer was extracted withEtOAc (50 mL). The combined organic extracts were washed with water(2×50 mL) and saturated NaCl aqueous solution (50 mL), dried over MgSO₄,and concentrated in vacuo. The crude desired product was directlyrecrystallized from 25% tert-butyl methyl ether (TBME)/heptanes (1:4v/v) to afford the desired2,2,2-trifluoro-N-(4-fluoro-3-cyano)phenylethanehydrazonyl tosylate (41,16.64 g, 20.05 g theoretical, 83%) as pale-yellow solids, which wasfound to be essentially pure to do the following cycloaddition reactionwithout further purification. For 41, CIMS m/z 400 (M⁺−H,C₁₆H₁₁F₄N₃O₃S).

Example 48

Ethyl1-(4-fluoro-3-cyano)phenyl-3-trifluoromethylpyrazoline-5-carboxylate(42)

A suspension of2,2,2-trifluoro-N-(4-fluoro-3-cyano)phenylethanehydrazonyl tosylate (41,802 mg, 2.0 mmol) in toluene (8 mL) was treated ethyl acrylate (400 mg,433 μL, 4.0 mmol, 2.0 equiv) at 0-5° C. under N₂, and resulting mixturewas added dropwise triethylamine (303 mg, 433 μL, 3.0 mmol, 1.5 equiv)at 0-5° C. under N₂. The resulting reaction mixture was then stirred at0-5° C. for 1 h before being gradually warmed up to 25° C. for 12 h.When HPLC and TLC showed that the reaction was deemed complete, thereaction mixture was directly purified by flash column chromatography(SiO₂, 0-20% EtOAc-hexanes gradient elution) to afford the desired ethyl1-(4-fluoro-3-cyano)phenyl-3-trifluoromethylpyrazoline-5-carboxylate(42, 572 mg, 658 mg theoretical, 87%) as pale-yellow oil, whichsolidified upon standing at room temperature in vacuo. For 42: CIMS m/z330 (M⁺+H, C₁₄H₁₁F₄N₃O₂); CIMS m/z 328 (M⁺−H, C₁₄H₁₁F₄N₃O₂).

Example 49

Ethyl 1-(4-fluoro-3-cyano)phenyl-3-trifluoromethylpyrazole-5-carboxylate(43)

A solution of ethyl1-(4-fluoro-3-cyano)phenyl-3-trifluoromethylpyrazoline-5-carboxylate(42, 395 mg, 1.2 mmol) in THF (4.0 mL) was treated withN-chlorosucinimide (NCS, 168 mg, 1.26 mmol, 1.05 equiv) at 0-5° C. underN₂, and the resulting reaction mixture was stirred at 0-5° C. for 10 minbefore being gradually warmed up to 25° C. for 2 h. When TLC and HPLCshowed that the reaction was deemed complete, the solvent was removed invacuo, and the residue was treated with H₂O (10 mL) and EtOAc (20 mL).The two layers were separated, and the aqueous layer was extracted withEtOAc (10 mL). The combined organic extracts were washed with H₂O (2×10mL), and saturated NaCl aqueous solution (10 mL), dried over MgSO₄, andconcentrated in vacuo. The residue was then purified by flash columnchromatography (SiO_(2, 10-25)% EtOAc-hexanes gradient elution) toafford the desired ethyl1-(4-fluoro-3-cyano)phenyl-3-trifluoromethylpyrazole-5-carboxylate (43,361 mg, 392 mg theoretical, 92%) as off-white solids. For 43: CIMS m/z326 (M⁺−H, C₁₄H₉F₄N₃O₂).

Example 50

1-(4-Fluoro-3-cyano)phenyl-3-trifluoramethylpyrazole-5-carboxylic acid(44)

A solution of ethyl1-(4-fluoro-3-cyano)phenyl-3-trifluoromethylpyrazole-5-carboxylate (43,160 mg, 0.49 mmol) in THF-MeOH-H₂O (3:1:1 v/v, 3 mL) was treated withlithium hydroxide monohydrate (LiOH-H₂O, 62 mg, 1.47 mmol, 3.0 equiv) at25° C. under N₂, and the resulting reaction mixture was stirred at 25°C. for 30 min. When HPLC and TLC showed the hydrolysis reaction wasdeemed complete, the solvents was removed in vacuo. The residue was thentreated with H₂O (10 mL) and EtOAc (5 mL). The two layers wereseparated, and the aqueous layer was extracted with EtOAc (5 mL). Thecombined organic extracts were discarded. The aqueous layer was thenacidified with 2 N HCl aqueous solution to pH 3.0 before being extractedwith EtOAc (2×15 mL). The combined organic extracts were then washedwith H₂O (2×5 mL) and saturated aqueous NaCl solution (5 mL), dried overMgSO₄, and concentrated in vacuo. The crude1-(4-fluoro-3-cyano)phenyl-3-trifluoromethylpyrazole-5-carboxylic acid(44, 139 mg, 147 mg theoretical, 95%) was obtained as white solids,which was found to be essentially pure to do the following reactionwithout further purification and to be identical with the materialobtained from another totally different synthetic approach in everycomparable aspect. For 44: CIMS m/z 298 (M⁺−H, C₁₂H₅F₄N₃O₂).

Example 51

N-(2-Fluoro-4-iodo)phenyl acrylamide (46)

A solution of 2-fluoro-4-iodoaniline (45, 11.85 g, 0.05 mol) in EtOAc(80 mL) was treated with acryloyl chloride (6.8 g, 6.1 mL, 0.075 mol,1.5 equiv) at 0-5° C. under N₂, and the resulting mixture was treateddropwise with a solution of N-methylmorpholine (NMM, 12.6 g, 13.7 mL,0.125 mmol, 2.5 equiv) in EtOAc (20 mL) at 0-5° C. under N₂. Thereaction mixture was stirred at 0-5 for 1 h before being quenched withwater (100 mL) and EtOAc (50 mL). The solids precipitated from themixture were collected by filtration, washed with water (100 mL) andTBME-hexane (1:2 v/v, 2×500 mL), and dried in vacuo at 40-45° C. for 12h to afford the first batch of the crude desiredN-(2-fluoro4-iodo)phenyl acrylamide (46, 9.14 g, 14.55 g theoretical,62.8%) as white solids, which was found to be >99% pure by HPLC. The twolayers of the filtrates were then separated, and the aqueous layer wasextracted with EtOAc (50 mL). The combined organic extracts were washedwith H₂O (100 mL) and saturated aqueous NaCl solution (100 mL), driedover MgSO₄, and concentrated in vacuo to afford the second batch of thecrude desired N-(2-fluoro-4-iodo)phenyl acrylamide (46, 4.1 g, 14.55 gtheoretical, 28.2%; total 91% yield) as off-white solids, which was alsofound to be pure enough to do the following reaction without furtherpurification. The analytically pure product (46) was obtained fromdirect recrystalization of the crude 46 obtained above fromEtOAc/heptanes. For 46: CIMS m/z 292 (M⁺+H, C₉H₇FINO).

Example 52

5-(2-Fluoro-4-iodo)phenylcarbamoyl-1-(4-fluoro-3-cyano)phenyl-3-trifluoromethyl-pyrazoline(47)

A suspension of2,2,2-trifluoro-N-(4-fluoro-3-cyano)phenylethane-hydrazonyl tosylate(41, 5.29 g, 13.2 mmol) in ethyl acetate (80 mL) was treated withN-(2-fluoro-4-iodo)phenyl acrylamide (46, 3.492 g, 12.0 mmol, 0.91equiv) at room temperature under N₂, and the resulting reaction mixturewas cooled down to 0-5° C. before being treated with N-methylmorpholine(NMM, 3.3 g, 3.6 mL, 30.0 mmol, 2.5 equiv) at 0-5° C. under N₂. Thereaction mixture was stirred at 0-5° C. for 30 min before beinggradually warmed up to room temperature for 1 h. The clear solution wasthen warmed up to 55° C. for an additional 4 h. When HPLC and TLC showedthat the reaction was deemed complete, the reaction mixture was cooleddown to room temperature before being treated with H₂O (50 mL). Themixture was stirred at room temperature for 30 min. The precipitateswere collected by filtration, washed with H₂O (2×30 mL) andEtOAc/hexanes (1:1 v/v, 2×20 mL), dried at 40-45° C. in vacuo for 12 hto afford the crude desired5-(2-fluoro-4-iodo)phenylcarbamoyl-1-(4-fluoro-3-cyano)phenyl-3-trifluoromethyl-pyrazoline(47, 2.6 g, 6.24 g theoretical, 41.7%) as white powder. The two layersof the filtrates were then separated, and the aqueous layer wasextracted with EtOAc (50 mL). The combined organic extracts were washedwith H₂O (2×50 mL) and saturated NaCl aqueous solution (50 mL), driedover MgSO₄, and concentrated in vacuo. The residual slurry of the crudeproduct (47) in EtOAc (20 mL) was the titrated with heptanes (100 ml),and the resulting mixture was stirred at room temperature for 30 min.The precipitates were then collected by filtration, washed with heptanes(2×20 mL), dried at 40-45° C. in vacuo for 12 h to afford the secondbatch of the crude desired5-(2-fluoro-4-iodo)phenylcarbamoyl-1-(4-fluoro-3-cyano)phenyl-3-trifluoromethyl-pyrazoline(47, 2.2 g, 6.24 g theoretical, 35.3%; total 77% yield) as white powder.The crude product (47) obtained above was found to be pure enough to dothe following reaction without further purification. The analyticallypure product (47) was obtained from recrystalization of the crudematerial from EtOAc-heptanes. For 47: CIMS m/z 519 (M⁺−H, C₁₈H₁₀F₅IN₄O).

Example 53

5-(2-Fluoro-4-iodo)phenylcarbanoyl-1-(4-fluoro-3-cyano)phenyl-3-trifluoromethyl--pyrazole(48)

A suspension of5-(2-fluoro-4-iodo)phenylcarbamoyl-1-(3-cyano)phenyl-3-trifluoromethylpyrazoline(47, 3.90 g, 7.5 mmol) in THF (30 mL) was treated withN-chlorosuccinimide (NCS, 1.05 g, 7.88 mmol, 1.05 equiv) at 0-5° C., andthe resulting reaction mixture was gradually warmed to room temperaturefor 2 h. When the HPLC and TLC showed the reaction was deemed complete,the solvent was removed in vacuo and the residue was treated with water(50 mL) and EtOAc-heptanes (1:4 v/v, 30 mL). The mixture was stirred atroom temperature for 30 min, and the solids were collected byfiltration, washed with EtOAc-heptanes (1:4 v/v, 2×30 mL), and dried at40-45° C. in vacuo for 12 h to afford the crude desired5-(2-fluoro-4-iodo)phenylcarbamoyl-1-(4-fluoro-3-cyano)phenyl-3-trifluoromethyl-pyrazole(48, 3.79 g, 3.89 g theoretical, 97.4%) as off-white powder, which wasfound to be >99% by HPLC and was used in the following reaction withoutfurther purification. The analytically pure product (48) was obtainedfrom recrystallization of the crude product obtained above fromEtOAc/heptanes. For 48: CIMS m/z 517 (M⁺−H, C₁₈H₈F₅IN₄O).

Example 54

5-(2-Fluoro-4-iodo)phenylcarbamoyl-1-[3-cyano-4-(dimethylmethyleneimino)oxy]-phenyl-3-trifluoromethylpyrazole(49)

A solution of acetone oxime (657 mg, 9.0 mmol, 3.0 equiv) in anhydrousTHF (4.0 mL) was added to a suspension of sodium hydride (NaH, 60% oildispersion in mineral oil, 384 mg, 9.6 mmol, 3.2 equiv) in anhydrous THF(4.0 mL) at 0-5° C. under N2, and the resulting mixture was stirred at0-5° C. for 30 min before being treated a solution of5-(2-fluoro-4-iodo)phenylcarbamoyl-1-(4-fluoro-3-cyano)phenyl-3-trifluoromethyl-pyrazole(48, 1.554 g, 3.0 mmol) in anhydrous DMF (8.0 mL) at 0-5° C. under N₂.The resulting reaction mixture was subsequently stirred at 0-5° C. for10 min before being gradually warmed up to 25° C. for an additional 30min. When TLC and HPLC showed that the reaction was deemed complete, thereaction mixture was treated with H₂O (50 mL), and the mixture wasstirred at room temperature for 30 min. The off-white precipitates werethen collected by filtration, washed with H₂O (2×10 mL) andEtOAc-heptanes (1:4 v/v, 2×20 mL), and dried at 40-45° C. in vacuo for12 h to afford the crude desired5-(2-fluoro-4-iodo)phenylcarbamoyl-1-[3-cyano-4-(dimethylmethyleneimino)oxy]-phenyl-3-trifluoromethylpyrazole(49, 1.576 g, 1.713 g theoretical, 92%), Which was found to be >99% pureby HPLC and was used in the following reaction without furtherpurification. The analytically pure product (49) was obtained byrecrystallization of crude material obtained above from EtOAc-heptanes.For 49: CIMS m/z 570 (M⁺−H, C₂₂H₁₄F₄IN₅O₂).

Example 55

5-(2-Fluoro-4-iodo)phenylcarbamoyl-1-[(3-amino)benz[d]isoxazol-6-yl]-3-trifluoro-methylpyrazole(50)

A suspension of5-(2-fluoro-4-iodo)phenylcarbamoyl-1-[3-cyano-4-(dimethylmethyleneimino)oxy]phenyl-3-trifluoromethylpyrazole(49, 571 mg, 1.0 mmol) in 5-6 N HCl in isopropyl alcohol (4 mL) waswarmed up to reflux for 4 h. When HPLC and TLC showed that the reactionwas deemed complete, the solvent was removed in vacuo, and the residuewas treated with saturated Na₂CO₃ aqueous solution (10 mL) and EtOAc (20mL). The two layers were separated, and the aqueous layer was extractedwith EtOAc (10 mL). The combined organic extracts were washed with H₂O(2×10 mL) and saturated NaCl aqueous solution (10 mL), dried over MgSO₄,and concentrated in vacuo. The residue was purified by flash columnchromatography (SiO₂, 10-30% EtOAc-hexanes gradient elution) to affordthe desired5-(2-fluoro-4-iodo)phenylcarbamoyl-1-[(3-amino)benz[d]isoxazol-6-yl]-3-trifluoro-methylpyrazole(50, 427 mg, 531 mg theoretical, 80.4%) as white solids. For 50: CIMSm/z 529/531 (M⁺−H, C₁₈H₁₀F₄IN₅O₂).

Obviously, numerous modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims, theinvention may be practiced otherwise than as specifically describedherein.

What is claimed is:
 1. A process for preparing a compound of formula I:

wherein ring D is selected from 2-(aminomethyl)phenyl,3-(aminomethyl)phenyl, and (3-amino)benz[d]isoxazol-6-yl; and B is2-MeSO₂-phenyl or 2-NH₂SO₂-phenyl, the process comprising: (a) acylatinga hydrazine of formula II to form a compound of formula III:

wherein ring D is selected from 2-cyanophenyl, 3-cyanophenyl,3-cyano-4-fluorophenyl, 2-(PgNHCH₂)phenyl, and 3-(PgNHCH₂)phenyl, and Pgis an amine protecting group; (b) converting a compound of formula IIIto a compound of formula IV, wherein X is selected from Cl, OMs, Br,OSO₂Ph, and OTs; (c) contacting a compound of formula IV with a base toform a dipolar compound of formula V:

(d) contacting a compound of formula V in situ with a dipolarophile offormula VI to form a compound of formula VII, wherein Y is selected fromBr, 2-MeSO₂-phenyl, 2-MeS-phenyl, 2-NH₂SO₂-phenyl, and 2-PgNHSO₂-phenyl;(e) converting a compound of formula VII to a compound of formula I bysubjecting it to the following reactions, which may be performed, whenapplicable, in any order: (e1) oxidizing the pyrazoline to a pyrazole;(e2a) when Y=Br, converting the Br group to 2-MeS-phenyl,2-SO₂Me-phenyl, or 2-SO₂NH₂-phenyl; (e2b) when Y=2-MeS-phenyl,converting the MeS-group to MeSO₂—; (e3a) when ring D is cyanophenyl,converting this group to aminomethylphenyl or (PgNHCH₂)phenyl; (e3b)when ring D is 3-cyano-4-fluorophenyl, converting this ring to(3-amino)benz[d]isoxazol-6-yl; and, (e4) when Pg is present, removingthe protecting group.
 2. A process according to claim 1, wherein step(b) is performed by contacting a compound of formula III with a sulfonylchloride in the presence of an amine base to form a compound of formulaIV wherein X is Cl; wherein the sulfonyl chloride is selected frommethylsulfonyl chloride, phenylsulfonyl chloride and toluenesulfonylchloride, the amine base is selected from triethylamine,diisopropylethylamine, and N-methylmorpholine.
 3. A process according toclaim 2, wherein the sulfonyl chloride is phenylsulfonyl chloride theamine base is diisopropylethylamine.
 4. A process according to claim 2,wherein ring D is 3-(aminomethyl)phenyl, B is 2-MeSO₂-phenyl, Y is2-MeS-phenyl, and step (e) is performed in the following order: (e1)oxidizing the pyrazoline to a pyrazole; (e2b) converting the MeS-groupto MeSO₂—; and, (e3a) converting the cyanophenyl group to3-(aminomethyl)phenyl.
 5. A process according to claim 2, wherein ring Dis 3-(aminomethyl)phenyl, B is 2-MeSO₂-phenyl, Y is Br; and step (e) isperformed in the following order: (e1) oxidizing the pyrazoline to apyrazole; (e2a) converting the Br group to 2-MeS-phenyl; (e2b)converting the MeS-group to MeSO₂—; and, (e3a) converting thecyanophenyl group to 3-(aminomethyl)phenyl.
 6. A process according toclaim 1, wherein in (e) the compound of formula VII is converted to acompound of formula I by subjecting compound VII to the followingreactions, that are performed, when applicable, in the order shown: (e1)oxidizing the pyrazoline to a pyrazole; (e2a) when Y=Br, converting theBr group to 2-MeS-phenyl, 2-SO₂Me-phenyl, or 2-SO₂NH₂-phenyl; (e2b) whenY=2-MeS-phenyl, converting the MeS-group to MeSO₂—; (e3a) when ring D iscyanophenyl, converting this group to aminomethylphenyl or(PgNHCH₂)phenyl; (e3b) when ring D is 3-cyano-4-fluorophenyl, convertingthis ring to (3-amino)benz[d]isoxazol-6-yl; and, (e4) when Pg ispresent, removing the protecting group.
 7. A process according to claim1, wherein in (e) the compound of formula VII is converted to a compoundof formula I by subjecting compound VII to the following reactions, thatare performed, when applicable, in the order shown: (e1) oxidizing thepyrazoline to a pyrazole; (e3a) when ring D is cyanophenyl, convertingthis group to aminomethylphenyl or (PgNHCH₂)phenyl; (e3b) when ring D is3-cyano-4-fluorophenyl, converting this ring to(3-amino)benz[d]isoxazol-6-yl; (e2a) when Y=Br, converting the Br groupto 2-MeS-phenyl, 2-SO₂Me-phenyl, or 2-SO₂NH₂-phenyl; (e2b) whenY=2-MeS-phenyl, converting the MeS-group to MeSO₂—; and, (e4) when Pg ispresent, removing the protecting group.
 8. A process according to claim1, wherein in (e) the compound of formula VII is converted to a compoundof formula I by subjecting compound VII to the following reactions, thatare performed, when applicable, in the order shown: (e2a) when Y=Br,converting the Br group to 2-MeS-phenyl, 2-SO₂Me-phenyl, or2-SO₂NH₂-phenyl; (e2b) when Y=2-MeS-phenyl, converting the MeS-group toMeSO₂—; (e1) oxidizing the pyrazoline to a pyrazole; (e3a) when ring Dis cyanophenyl, converting this group to aminomethylphenyl or(PgNHCH₂)phenyl; (e3b) when ring D is 3-cyano-4-fluorophenyl, convertingthis ring to (3-amino)benz[d]isoxazol-6-yl; and, (e4) when Pg ispresent, removing the protecting group.
 9. A process according to claim1, wherein in (e) the compound of formula VII is converted to a compoundof formula I by subjecting compound VII to the following reactions, thatare performed, when applicable, in the order shown: (e2a) when Y=Br,converting the Br group to 2-MeS-phenyl, 2-SO₂Me-phenyl, or2-SO₂NH₂-phenyl; (e2b) when Y=2-MeS-phenyl, converting the MeS-group toMeSO₂—; (e3a) when ring D is cyanophenyl, converting this group toaminomethylphenyl or (PgNHCH₂)phenyl; (e3b) when ring D is3-cyano-4-fluorophenyl, converting this ring to(3-amino)benz[d]isoxazol-6-yl; (e1) oxidizing the pyrazoline to apyrazole; and, (e4) when Pg is present, removing the protecting group.10. A process according to claim 1, wherein in (e) the compound offormula VII is converted to a compound of formula I by subjectingcompound VII to the following reactions, that are performed, whenapplicable, in the order shown: (e3a) when ring D is cyanophenyl,converting this group to aminomethylphenyl or (PgNHCH₂)phenyl; (e3b)when ring D is 3-cyano-4-fluorophenyl, converting this ring to(3-amino)benz[d]isoxazol-6-yl; (e1) oxidizing the pyrazoline to apyrazole; (e2a) when Y=Br, converting the Br group to 2-MeS-phenyl,2-SO₂Me-phenyl, or 2-SO₂NH₂-phenyl; (e2b) when Y=2-MeS-phenyl,converting the MeS-group to MeSO₂—; and, (e4) when Pg is present,removing the protecting group.
 11. A process according to claim 1,wherein in (e) the compound of formula VII is converted to a compound offormula I by subjecting compound VII to the following reactions, thatare performed, when applicable, in the order shown: (e3a) when ring D iscyanophenyl, converting this group to aminomethylphenyl or(PgNHCH₂)phenyl; (e3b) when ring D is 3-cyano-4-fluorophenyl, convertingthis ring to (3-amino)benz[d]isoxazol-6-yl; (e2a) when Y=Br, convertingthe Br group to 2-MeS-phenyl, 2-SO₂Me-phenyl, or 2-SO₂NH₂-phenyl; (e2b)when Y=2-MeS-phenyl, converting the MeS-group to MeSO₂—; (e1) oxidizingthe pyrazoline to a pyrazole; and, (e4) when Pg is present, removing theprotecting group.
 12. A compound of formula IX:

wherein ring D is 2-cyanophenyl, 2-(PgNHCH₂)phenyl,2-(aminomethyl)phenyl, 3-cyanophenyl, 3-(PgNHCH₂)phenyl,3-(aminomethyl)phenyl, 3-cyano-4-fluorophenyl, and(3-amino)benz[d]isoxazol-6-yl; Y′ is selected from Br, H, PgHNSO₂Ph,H₂NSO₂Ph, 2-MeSPh, and 2-MeSO₂Ph; bond a is absent or is a single bond;and, Pg is an amine protecting group selected from Boc and TFA.